NEOntometrics Ontology Metrics Ontology.
type: Ontology
comment: An ontology for describing ontology metrics. It contains the underlying information of the NEOntometrics application by connecting database and calculation values with background information and proposed metric frameworks.
comment: The individuals stored in this ontology correspond to metric values that are calculated and stored in the database. They are connected to subclasses from the class Elemental Metrics. These kind of metrics describe atomic measurements for assessing ontologies. The elemental metrics are then connected by mathematical relations to subclasses of "Quality Frameworks". These frameworks represent metric calculations as proposed in the literature.

MetricDefinition
type: AnnotationProperty
comment: A formal definiton for the metric given by the framework's authors.

MetricDescription
type: AnnotationProperty
comment: A description for the element given be the metric/frameworks authors.

MetricInterpretation
type: AnnotationProperty
comment: A guideline by the author of the framework how to interpret a given value.

QualityImplication
type: ObjectProperty
sub property of: topObjectProperty
metric definition: Connects ontology metrics to quality implications.
metric description: Some of the frameworks not only propose ontology metrics, but also connect these metrics to quality dimensions like "Maintainablility" or "Reusability". The implications are mapped using these connections.
metric interpretation: Not yet implemented in NEOntometrics.

affectsNegative
type: ObjectProperty
sub property of: QualityImplication
inverse of: negativeAffectedBy
metric definition: states that a metric negatively affects a quality dimension.

affectsPositive
type: ObjectProperty
sub property of: QualityImplication
inverse of: positiveAffectedBy
property disjoint with: positiveAffectedBy
metric definition: states that a metric positively affects a quality dimension.

calculatedBy
type: ObjectProperty
domain: Quality Frameworks
range: Elemental Metrics
metric description: The relation asserts how a metric is decomositioned into the essential Metrics

directlyUsesMetric
type: ObjectProperty
sub property of: calculatedBy
metric definition: States that a metric directly uses the given Elemental Metrics.
metric description: An Example for this property is oquals "Maximum Depth" measurement. While it originates from a framework, it does not propose a ratio between two measurements, but directly reuses the Elemental_Metric "maximum depth".

division
type: ObjectProperty
sub property of: calculatedBy
metric definition: use the following: "numerator only METRIC_A and divisor only METRIC_B" Do not use the division-class directly!
metric description: Represents the composition of a ratio-value through the use of its subclasses numerator and divisor.

divisor
type: ObjectProperty
sub property of: division
metric definition: The Divisor in a fraction.

implementedBy
type: ObjectProperty
domain: Elemental Metrics
range: Individuals
metric definition: Points from the elemental metrics to the individuals representing the actual measurements in database and calculation engine.

minuend
type: ObjectProperty
sub property of: subtraction
metric definition: The minuend in a substraction.

multiplication
type: ObjectProperty
sub property of: calculatedBy
metric definition: Multiplication of two values.

negativeAffectedBy
type: ObjectProperty
sub property of: QualityImplication
domain: Quality Dimension
range: Quality Frameworks
metric definition: States that a quality dimension is negatively affected by a metric.

numerator
type: ObjectProperty
sub property of: division
metric definition: The Numerator in a fraction.

positiveAffectedBy
type: ObjectProperty
sub property of: QualityImplication
domain: Quality Dimension
range: Quality Frameworks
metric definition: States that a quality dimension is positively affected by a metric.

similarTo
type: ObjectProperty
type: SymmetricProperty
metric definition: Defines that two framework metrics measures something similar (But not the same)
metric interpretation: Even though this measurement indeed says that two things measure the same element, saying that they are equivalent in description logic has large side effects, so we use this similarTO relation.

standardDeviationOf
type: ObjectProperty
sub property of: calculatedBy
metric description: Calculates the Standard Deviation of a set of values. Takes a list of values as an input

subtraction
type: ObjectProperty
sub property of: calculatedBy
metric definition: The relations to handle subtstractions of metrics.

subtrahend
type: ObjectProperty
sub property of: subtraction
metric definition: The subtrahend in a substraction.

sum
type: ObjectProperty
sub property of: calculatedBy
metric definition: States that two or more metrics are summed up.

All Imports
type: Class
subclass of: Special Metrics
subclass of: Restriction
  on property: implementedBy
  has value: allActualImports
metric definition: An array containing the imported ontologies (with transitive closure).
metric description: Often, an ontology imports other ontologies, to facilitate the reusing of knowledge or the seperation of concerns. This item shows all imported ontologies, including such with transitive closure.
metric interpretation: It means if A imports B, and B imports C, this for A, this metric shows B and C.

Annotation Assertions
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: annotationAssertionsAxioms
metric definition: All Annotations overall in the ontology
metric description: Non logical annotations on a class (e.g., rdfs:comment)

Annotation Properties
type: Class
subclass of: Elemental Metrics
metric definition: Metrics related to annotation properties.
metric description: Annotations provide human centered descriptions and explanations.

Annotation Property Domain Declarations
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: annotationPropertyDomainAxioms
metric definition: Counts the number of annotation domain declarations of the annotation properties.
metric description: Annotation Domain restrictions in the settings of the annotation properties limit the classes on where an annotation can be put. If "Class" (1) "hasAnnotation" (2) "Annotation" (3), the class (1) is limited through the domain element.

Annotation Property Range Declarations
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: annotationPropertyRangeaxioms
metric definition: Counts the number of annotation range declarations of the (custom) annotation properties.
metric description: Annotation Range restrictions in the settings of the annotation properties limit the types or classes that can be used as an annotation. If "Class" (1) "hasAnnotation" (2) "Annotation" (3), the annotation (3) is limited through the Range element. Examples are datatypes like "xsd:integer" or other classes (if these other classes are used as annotations for a class)

Annotations On Classes
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: classAnnotations
metric description: Annotations can be put on almost all elements of the ontology. This metric counts how many annotation elements are put on classes.
comment: Counts the number of Annotations on Classes.

Annotations On Data Properties
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: dataPropertyAnnotations
metric definition: Counts the number of annotations on data properties.
metric definition: This metric counts how manny annoations are put on data properties E.g., hasAge -> "How old a thing is"

Annotations On Datatypes
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: datatypeAnnotations
metric definition: Counts the number of annotations on datatypes.
metric description: Counts the number of annotation on data types (e.g., xsd:Int)

Annotations On Individuals
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: individualAnnotations
metric definition: Counts the number of annotations on individuals.
metric description: Counts the number of annotation on individuals (or instances). E.g. Individual 'Herbert' which is an instance of the class 'Person' has the Annotation 'rdfs:comment: Nice person"

Annotations On Object Properties
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: objectPropertyAnnotations
metric definition: Counts the number of annotations on object properties.
metric description: Measures the annotations set on object properties, thus relations between classes. E.g.: inLoveWith -> The romantical feeling to one another.

Annotations On Ontology
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: generalAnnotationAxioms
metric definition: Counts the number of annotations on the ontology in general.
metric description: Counts the annotations set on the ontology in general. E.g.,: "This is an ontology about family relations"

Annotations on Class
type: Class
subclass of: Class Metrics
metric definition: Number of annotations on a class.
metric description: Calculates the number of human centered class annotations. This can be based on built-in annotation properties like e.g., rdfs:comment, or rdfs:seeAlso, or self-created properties.

Anonymous Classes
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: anonymousClasses
metric description: Class expressions that are not classes itself (e.g., relations)

Asymmetric Object Properties
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: asymmetricObjectPropertyAxioms
metric definition: Counts the number of object properties that are "asymmetric"
metric description: If an object property is asymmetric, and a relation of individual A->B exist, then there can be no relation B->A. E.g., the parentOf would be asymmetric.

Author Name
type: Class
subclass of: Repository Metrics
subclass of: Restriction
  on property: implementedBy
  has value: AuthorName
metric definition: Git-Based Information. The name of the person who made the change.

Axioms
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: axioms
metric definition: The number of axioms declared in an ontology.
metric description: The building blocks of an ontology. Triple that state a fact about the conceptualized reality (e.g.Rat rdfs:subClassOf Animal) is an Axiom.
metric interpretation: Every other metric is, at least in a way, derived from the axioms that form the conceptualization we want to analyze.The larger this axioms number is, the larger is the ontology normally. However, an axiom can be anything. Like a class declaration, an annotation or relationship assertions. So a larger number of axioms does not necessarly mean the ontology is more complex, it could also be a a mere taxonomy (is-a statements).

Basic Metrics
type: Class
subclass of: Elemental Metrics
metric definition: The building blocks of every ontology.
metric description: Metrics that measure the very basic constructs every ontology consists of.

Breath Metrics
type: Class
subclass of: Graph Metrics
metric definition: Metrics concerned with the width of the Graph
metric description: Breath metrics measure aspects regarding the siblings in an ontology graph. Sibblings are classes that are on the same inheritance (e.g., with one sub class distance from the root classes).

Class Assertions
type: Class
subclass of: Instances Metrics
subclass of: Restriction
  on property: implementedBy
  has value: classAssertionaxioms
metric definition: Counts the number of assertions from instances to classes.
metric description: A declared individual (or instance) can belong to none, one or many classes (as long as they are not disjoint).

Class Metrics
type: Class
subclass of: Iterative Metrics
metric definition: Metrics that are calculated per class in the ontology.
metric description: Class Metrics give an further insight into the individual classes. They are calculated once for every class in the ontology.

Classes (Class Count)
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: classes
metric definition: The number of declared classes in the ontology.E.g, through rdfs:subClassOf or owl:Class declarations.
metric description: Classes are the objects that the ontology describes further. They are the objects in our conceptualizations, the elements that we want to link with each other. Taking the W3C definition, "A class defines a group of individuals that belong together because they share some properties"
metric interpretation: The higher the number of classes, the larger is our universe of discourse. An ontology that defines a large number of classes, thus can be considered "large"

Classes In Cycles
type: Class
subclass of: Graph Metrics
metric definition: The number of classes in cycles
metric description: Cycles are subclass relationships like A subClassOf B; B subClassOf C, C subClassOf A. This metrics counts the number of classes in these kind of cycles.
metric interpretation: Cycles are ususally bad ontology design. Please note that the occurence of cycles in the ontology prevents a lot of further calculations (e.g., how to measure depth of there are cyclic sub class relationships. Further, most reasoners cannot work with cycles in the ontology, thus detecting (rightfully so) inconsistencies.

Classes That Share A Relation
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: classesThatShareARelation
metric description: The number of classes that use share a relation with another class.
metric interpretation: Can be used to determine whether the usage of the various relation properties is rather diverse or homogenous.

Classes with Instances
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: classesWithIndividuals
metric definition: The number of Classes that have asserted individuals
metric description: Ontologies are often used to structure actual items into abstract concepts (e.g. "Peter" is an individual of the class "Human"). This number shows how many of the abstract concepts actually have a instances (also often named "individuals").
metric interpretation: Can be used to find how much of the ontological structure of a knowledge base is used, and how much is e.g., obsolete.

Classes with Multiple Inheritance
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: classesWithMultipleInheritance
metric definition: The number of classes that have more than one parent.
metric description: Depending on the kind of conceptualization, a class often belongs to more than one parent. (E.g., A "human" could be part of "mammal" and "carnivore").
metric interpretation: For some kind of conceptualizations, one might want to discourage multi-inheritance relationships.Often, these mutli-inheritance relationships make the ontology harder to understand and also increases the chance of incoonsistencies in combination with the usage of disjoint axioms.

Classes With Relations
type: Class
subclass of: Property Metrics
subclass of: Restriction
  on property: implementedBy
  has value: classesWithObjectProperties
metric description: Number of Classes that are connected to other classes using Object Properties

Classes With Subclasses
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: classesWithSubClasses
metric definition: Number of Classes that have subclasses
metric definition: The number of classes that have subclasses (and are, thus, not leaf classes)
metric description: Counts the number of classes that have children (Thus, all classes that are not leaf classes)
metric interpretation: This metric (in composition with others) can tell much on the structure of the ontology graph. E.g., many leaf classes and just a few "classes with subclasses" indicate a shallow ontology
label: Number of Root Classes

CohesionMetrics ADIT-LN
type: Class
subclass of: Cohesion Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Paths Overall
  intersection of: Restriction
    on property: numerator
    all values from: Total Depth
metric definition: Average Depth of Inheritance Tree of all Leaf Nodes, ADIT-LN is the sum of depths of all paths divided by the total number of paths. A depth is the total number of nodes. A depth is the total number of nodes starting from the root node to the leaf node in a path. The total number of paths in an ontology is all distinct paths from each root node to each leaf node if there exists an inheritance path from the root node to the leaf node. And root node is the first level in each path.
metric description: cohesion metrics ADIT-LN is a direct measure to count the depth of the inheritance tree for all leaf nodes measurement: (classes) in ontologies.

CohesionMetrics NoL
type: Class
subclass of: Cohesion Metrics
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Leaf Classes
metric definition: Number of Leaf Classes (NoL) is the number of leaf classes explicitly defined in the ontology Oi . A leaf class in an ontology means the class has no semantic subclass explicitly defined in the ontology Oi.
metric description: Count the Leaf Classes in Ontologies

CohesionMetrics NoR
type: Class
subclass of: Cohesion Metrics
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Classes With Subclasses
metric definition: Number of Root Classes (NoR) is the number of root classes explicitly defined in the ontology Oi . A root class in an ontology means the class has no semantic super class explicitly defined in the ontology Oi.
metric description: Count the root nodes (classes) in ontologies

Cohesion Metrics
type: Class
subclass of: Quality Frameworks
see also: Yao, Haining; Orme, Anthony Mark; Etzkorn, Letha (2005): Cohesion Metrics for Ontology Design and Application. In J. of Computer Science 1 (1), pp. 107–113. DOI: 10.3844/jcssp.2005.107.113.

Comitter Name
type: Class
subclass of: Repository Metrics
subclass of: Restriction
  on property: implementedBy
  has value: CommitterName
metric definition: Git-Based Information. The name of the person who commits the change.

Commit ID
type: Class
subclass of: Repository Metrics
subclass of: Restriction
  on property: implementedBy
  has value: CommitID
metric definition: Git-Based Information. A Hex-Information that unambigously identifies a commit in a repository.

Commit Message
type: Class
subclass of: Repository Metrics
subclass of: Restriction
  on property: implementedBy
  has value: CommitMessage
metric definition: Git-Based Information. The (manually provided) git commit message.

Commit Time
type: Class
subclass of: Repository Metrics
subclass of: Restriction
  on property: implementedBy
  has value: CommitTime
metric definition: Git-Based Information. The date and time when the commit occured.

Committer Email
type: Class
subclass of: Repository Metrics
subclass of: Restriction
  on property: implementedBy
  has value: CommiterEmail
metric description: The E-Mail of the person who accepts the commit.

ComplexityMetrics Average Path Length
type: Class
subclass of: Complexity Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Restriction
      on property: sum
      all values from: Class
        intersection of: Subclasses of Thing
        intersection of: Super Classes
  intersection of: Restriction
    on property: numerator
    all values from: Total Depth
metric definition: The average path length of the ontology.
metric interpretation: Please note that the number of pathes is understood in this paper as the number of connections of all concepts to the root classes. For our calculation engine, that is equivalent to the number of Superclasses (As it states how many connections there are to the top) plus the number of subclasses of thing. The latter is necessary as these metrics would not otherwise be counted as they have no superclasses. But for the given metric framework, these top level concepts are counted as the first hierachical level

ComplexityMetrics Average Paths Per Concept
type: Class
subclass of: Complexity Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Restriction
      on property: sum
      all values from: Class
        intersection of: Subclasses of Thing
        intersection of: Super Classes
metric interpretation: Average Paths Per Concept must be equal to or greater than 1 (each concept must have a parent except for the most general concept). If =1 then the ontology is a tree. Multi relation cocepts multi relation concepts(higher "average relationships per concept ratio ratio) result in gy higher ρ ratio for an ontology Please note that the number of pathes is understood in this paper as the number of connections of all concepts to the root classes. For our calculation engine, that is equivalent to the number of Superclasses (As it states how many connections there are to the top) plus the number of subclasses of thing. The latter is necessary as these metrics would not otherwise be counted as they have no superclasses. But for the given metric framework, these top level concepts are counted as the first hierachical level

ComplexityMetrics Average Relationships Per Concept
type: Class
subclass of: Complexity Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Object Property Assertions
metric definition: The average relations per concept in an ontology
metric description: Indicates the average connectivity degree of a concept
metric interpretation: MetricInterpretation "Please note that the number of pathes is understood in this paper as the number of connections of all concepts to the root classes. For our calculation engine, that is equivalent to the number of Superclasses (As it states how many connections there are to the top) plus the number of subclasses of thing. The latter is necessary as these metrics would not otherwise be counted as they have no superclasses. But for the given metric framework, these top level concepts are counted as the first hierachical level"

ComplexityMetrics TNOC
type: Class
subclass of: Complexity Metrics
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Classes (Class Count)
metric definition: Total Number Of Concepts: The number of concepts in the set.
metric interpretation: As ontology consists of concepts and relations, TNOC and TNOR are the two basic attributes of ontology, we can see the change of basic size of an ontology by analyzing these two attributes. As path consists of relations and can reflect the inner structure and hierarchy of ontology,

ComplexityMetrics TNOP
type: Class
subclass of: Complexity Metrics
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Paths Overall
metric definition: Total number of Paths: The sum of paths of each concept.
metric description: A path is a distinct trace in direct acyclic graph from a specific particular concept to the most general concept in the ontology, which is the concept without any parent or superclass(
metric interpretation: TNOP represents an ontology’s hierarchical complexity and its value is proportionate to difficulties in navigating and visualizing the ontology[

ComplexityMetrics TNOR
type: Class
subclass of: Complexity Metrics
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Sub Class Declarations
metric definition: Total Number Of Relations: The sum of the number of relations of each concept in an ontology.
metric interpretation: As ontology consists of concepts and relations, TNOC and TNOR are the two basic attributes of ontology, we can see the change of basic size of an ontology by analyzing these two attributes. As path consists of relations and can reflect the inner structure and hierarchy of ontology,

Complexity Cohesion
type: Class
subclass of: Quality Frameworks
metric definition: - Let P1,P2,.. . ,Pn be the set of n properties defined in an ontology. - Let C1,C2,... ,Cm be the set of m classes defined in an ontology. - Let Fc1,Fc2,... , Fcm be the Fanout of each class Ci (see below for the definition of Fanout). - Let O1 be the ontology of interest. - Let -> be a mapping from set Ci ,to Cj such that Ci -> Cj if class Cj is a subclass of class Ci - Let & be a mapping from set Ci to set Pj such that Ci & Pj if class Ci includes property Pj as part of its definition.
see also: Orme, Anthony Mark; Yao, Haining; Etzkorn, Letha H. (2007): Indicating ontology data quality, stability, and completeness throughout ontology evolution. In Journal of Software Maintenance and Evolution 19 (1), pp. 49–75. DOI: 10.1002/smr.341.

Complexity Metrics
type: Class
subclass of: Quality Frameworks
see also: Yang, Zhe; Zhang, Dalu; Ye, Chuan (2006): Ontology Analysis on Complexity and Evolution Based on Conceptual Model. In Ulf Leser (Ed.): Data integration in the life sciences. Third international workshop, DILS 2006, Hinxton, UK, July 20 - 22, 2006 ; proceedings, vol. 4075. Berlin: Springer (Lecture notes in computer science Lecture notes in bioinformatics, 4075), pp. 216–223.

Computational Complexity
type: Class
subclass of: Special Metrics
subclass of: Restriction
  on property: implementedBy
  has value: dlExpressivity
metric definition: The DL-subset of the ontology.
metric description: Computational ontologies are build on description logic as their foundation. Description Logic comes in several subsets, depending on their expressivity. This element shows to which subset this ontology belongs.

Conditioned Metrics
type: Class
subclass of: Special Metrics
metric description: Metrics that count just a subset of all available metrics (Under a specific conditiion)

Connected Graphs
type: Class
subclass of: Graph Metrics
subclass of: Restriction
  on property: implementedBy
  has value: numberOfConnectedGraphs
metric definition: Measures the number of independent graphs in an ontology.
metric description: At times, an ontology does not only contain one large, interconnected graph, but "islands" that are independent from each other. This metric does measure if the subclasses of root classes are connected with each other (through object properties). If not, it shows how much graphs (graphs that start on root level) are isolated.
metric interpretation: Ontologies can get quite large. If there are "islands" within an ontology, it can make sense to seperate these into seperate ontology files, to reduce complexity.

Consistent Ontology
type: Class
subclass of: Special Metrics
subclass of: Restriction
  on property: implementedBy
  has value: consistencyCheckSuccessful
metric definition: Indicates whether the ontology is consistent. Needs reasoning enabled to be calculated
metric description: A reasoner can detect complex inconsistencies in an ontology. An inconsistent ontology contains statements that contradict each other (e.g., an individual is asserted in two disjoint classes).
metric interpretation: Please note that not all statements that are inconsistent automatically lead to a fully inconsistent ontologies. The reasoner will first try to exclude the statements of the resolution and mark these classes as "inconsistent"

Data Properties
type: Class
subclass of: Property Metrics
subclass of: Restriction
  on property: implementedBy
  has value: dataProperties
metric definition: The number of declared individual data properties
metric description: Data properties connnect individuals to literal values (e.g., a person has the literal "age" assigned

Data Property Assertions
type: Class
subclass of: Instances Metrics
subclass of: Restriction
  on property: implementedBy
  has value: dataPropertyAssertionAxioms
metric definition: Counts the number of used object properties in instances.
metric description: An individual (or instance) can be connected to none, one or many data properties. E.g., person "Homer" hasAge "42".

Data Property Characteristics
type: Class
subclass of: Property Metrics
metric description: Data properties can be further logically described using predefined attributes (like disjointness, equivalence). These statements are covered by this category.

Data Property Domain Declarations
type: Class
subclass of: Data Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: dataPropertyDomainAxioms
metric description: Counts the number of data property domain declarations.
metric description: Imagine the data property statements of the class Domain:"Person" "hasAge". Then we use the domain statement to restrict that the Data Property "hasAge" can only be linked to elements of the class "person.

Data Property Range Declarations
type: Class
subclass of: Data Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: dataPropertyRangeAxioms
metric description: Counts the number of data property range declarations.
metric description: Imagine the data property statements of the class "hasAge" Range:"xsd:integer". Then we use the range statement to restrict that the Data Property "hasAge" can only be linked to the datatype "xsd:integer"

Declared Imports
type: Class
subclass of: Special Metrics
subclass of: Restriction
  on property: implementedBy
  has value: directImports
metric definition: An array containing the imported ontologies.
metric description: Often, an ontology imports other ontologies, to facilitate the reusing of knowledge or the seperation of concerns. This item does show which ontologies are directly imported. (without transitive closure)
metric interpretation: It means if A imports B, and B imports C, this for A, this metric shows B.

Definied Relationships on Class
type: Class
subclass of: Class Metrics
metric definition: Counts the number of relationships on a class
metric description: This metrics counts how many relationships are asserted in the respective class.

Deprecated Classes
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: deprecatedClasses
metric definition: Counts how many classes are marked as "Deprecated"
metric interpretation: Some ontology developers do not like to delete their obsolete classes, as the knowledge would be lost. Instead, they mark them with the standardized annotation 'deprecated'. This tells other knowledge engineers to not use it further in upcoming versions, without loosing the modeled knowledge.

Deprecated Data Properties
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: deprecatedDataProperties
metric definition: Counts how many data properties are marked as "Deprecated"
metric interpretation: Some ontology developers do not like to delete their obsolete classes, as the knowledge would be lost. Instead, they mark them with the standardized annotation 'deprecated'. This tells other knowledge engineers to not use it further in upcoming versions, without loosing the modeled knowledge.

Deprecated Data Types
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: deprecatedDataTypes
metric definition: Counts how many data types are marked as "Deprecated"
metric interpretation: Some ontology developers do not like to delete their obsolete classes, as the knowledge would be lost. Instead, they mark them with the standardized annotation 'deprecated'. This tells other knowledge engineers to not use it further in upcoming versions, without loosing the modeled knowledge.

Deprecated Individuals
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: deprecatedIndividuals
metric definition: Counts how many individuals are marked as "Deprecated"
metric interpretation: Some ontology developers do not like to delete their obsolete classes, as the knowledge would be lost. Instead, they mark them with the standardized annotation 'deprecated'. This tells other knowledge engineers to not use it further in upcoming versions, without loosing the modeled knowledge.

Deprecated Object Properties
type: Class
subclass of: Annotation Properties
subclass of: Restriction
  on property: implementedBy
  has value: deprecatedObjectProperties
metric definition: Counts how many object properties are marked as 'Deprecated'
metric interpretation: Some ontology developers do not like to delete their obsolete classes, as the knowledge would be lost. Instead, they mark them with the standardized annotation 'deprecated'. This tells other knowledge engineers to not use it further in upcoming versions, without loosing the modeled knowledge.

Depth Metrics
type: Class
subclass of: Graph Metrics
metric description: Depth is concerend with the deepness of the graph. Deepness is a measure of the number of following subclass hierachies of a path.
metric description: Metrics concerning the Depth of the Metric

Different Individuals
type: Class
subclass of: Instances Metrics
subclass of: Restriction
  on property: implementedBy
  has value: differentIndividualsAxioms
metric definition: Counts the number of different individual assertions (or individual inequality)
metric description: The differrent individual axiom states that all of the respective individuals are different from each other. It is not possible to derive that these individual are equal.

Disjoint Classes
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: disjointClassesAxioms
metric definition: Number of "Disjoint Classes" Statements
metric description: In OWL, we can explicitly declare that classes are disjoint from one another. In result, if class A and B are disjoint, no individual that is of type A can at the same time be of type B.This metric counts the number of these statements.
metric interpretation: A high level of usage of Disjoints can indicate a more formalized semantic.

Disjoint Data Properties
type: Class
subclass of: Data Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: disjointDataPropertiesAxioms
metric definition: Counts the number of disjoint data property axioms.
metric description: States that one individual cannot have the same literal for the given disjoint values. E.g., if the value "Zip-Code" and "Age" of a person is disjoint, then an individual cannot have Zip-Code=18057, age=18057

Disjoint Object Properties
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: disjointObjectPropertyAxioms
metric definition: Counts the number of disjoint object property declarations
metric description: If two (or more) object properties are disjoint, then no individual can have both relations. (E.g., mother and father are disjoint, there is no person who is mother and father at the same time).

Elemental Metrics
type: Class
subclass of: Metrics
metric description: The "Elemental Metrics" are the "building blocks" of all other metrics proposed in the Frameworks. E.g., If a framework proposes an "attribute/class" Ratio, it consists of elemental metrics "Attributes" and "Classes"

Equivalent Classes
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: equivalentClassesAxioms
metric definition: Classes that are equivalent to each other are semantically the same. E.g., a "Father" isEquivalentTo "Dad".
metric definition: Counts the "EquivalentTo" statements in the ontology

Equivalent Data Properties
type: Class
subclass of: Data Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: equivalentDataPropertiesAxioms
metric definition: Counts the number of equivalence data property axioms.
metric description: If two data properties are equivalent, they are semantically the same. E.g., the german word "hatName" and "hasName"

Equivalent Object Properties
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: equivalentObjectPropertyAxioms
metric description: Counts the number of equivalent object property declarations.
metric description: Two object properties are semantically the same. (E.g., hasBrother equivalentTo hasMaleSibling.)

Functional Data Properties
type: Class
subclass of: Data Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: functionalDataPropertyAxioms
metric definition: States that an individual with a functional data property can have at most one distinct property
metric description: An example for a classical functional data property would be "birth day", as one person can have at most one birthday.

Functional Object Properties
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: functionalObjectPropertyAxioms
metric definition: Counts the number of object properties that are "functional"
metric definition: if a relation is functional, for each x, there can be at most one y connected. E.g., if "hasFather" is functional, then a person can have at most one father.

GCI Count
type: Class
subclass of: Special Metrics
subclass of: Restriction
  on property: implementedBy
  has value: gciCount
metric definition: Counts the number of General Concept Inclusions (GCI).
metric description: GCIs are a way to encode complex sub class relationships to unnamed entitities. E.g.: (HeartDisease and hasLocation some HeartValve) SubClassOf: CriticalDisease Here, a thing that is the subclass of the heartDisease and located near the heartValve is thus a critical disease, without explicitly naming it.

Good Ontology
type: Class
subclass of: Quality Frameworks
see also: Fernández, Miriam; Overbeeke, Chwhynny; Sabou, Marta; Motta, Enrico (2009): What Makes a Good Ontology? A Case-Study in Fine-Grained Knowledge Reuse. In Asunción Gómez-Pérez, Yong Yu, Ying Ding (Eds.): The semantic web. Fourth Asian conference, ASWC 2009, Shanghai, China, December 6 - 9, 2009 ; proceedings, vol. 5926. ASWC; Asian Semantic Web Conference. Berlin: Springer (Lecture notes in computer science, 5926), pp. 61–75.

Good Ontology Average Breath
type: Class
subclass of: Good Ontology Structural Ontology Measures
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Total Breath
metric definition: Average size of the levels of the ontology

Good Ontology Average Depth
type: Class
subclass of: Good Ontology Structural Ontology Measures
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Total Depth
metric definition: Average size of the branches of the given ontology

Good Ontology Breath Variance
type: Class
subclass of: Good Ontology Structural Ontology Measures
subclass of: Class
  intersection of: Restriction
    on property: minuend
    all values from: Maximum Breath
  intersection of: Restriction
    on property: subtrahend
    all values from: Minimum Breath
metric definition: Variance of the size of the levels in the ontology

Good Ontology Depth Variance
type: Class
subclass of: Good Ontology Structural Ontology Measures
subclass of: Class
  intersection of: Restriction
    on property: minuend
    all values from: Maximum Depth
  intersection of: Restriction
    on property: subtrahend
    all values from: Minimum Depth
metric definition: Variance of the size of the branches in the ontology

Good Ontology Direct Popularity
type: Class
subclass of: Good Ontology Knowledge Coverage and Popularity Measures
metric definition: Number of ontologies importing a given ontology

Good Ontology Maximum Breath
type: Class
subclass of: Good Ontology Structural Ontology Measures
subclass of: Restriction
  on property: similarTo
  some values from: OQual Maximal Breath
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Maximum Breath
metric definition: Size of the largest level of the ontology

Good Ontology Maximum Depth
type: Class
subclass of: Good Ontology Structural Ontology Measures
subclass of: Restriction
  on property: similarTo
  some values from: Depth of subsumption hierarchy
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Maximum Depth
metric definition: Size of the longest branch in the given ontology

Good Ontology Minimum Breath
type: Class
subclass of: Good Ontology Structural Ontology Measures
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Minimum Breath
metric definition: Size of the narrowest level of the ontology

Good Ontology Minimum Depth
type: Class
subclass of: Good Ontology Structural Ontology Measures
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Minimum Depth
metric definition: Size of the shortest branch in the given ontology

Good Ontology Number Of Classes
type: Class
subclass of: Good Ontology Knowledge Coverage and Popularity Measures
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Classes (Class Count)
metric definition: Number of classes in a given ontology

Good Ontology Number Of Individuals
type: Class
subclass of: Good Ontology Knowledge Coverage and Popularity Measures
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Individuals
metric definition: Number of individuals in a given ontology

Good Ontology Number Of Properties
type: Class
subclass of: Good Ontology Knowledge Coverage and Popularity Measures
subclass of: Restriction
  on property: sum
  all values from: Class
    intersection of: Data Properties
    intersection of: Object Properties
metric definition: Number of properties in a given ontology

Graph Metrics
type: Class
subclass of: Elemental Metrics
metric definition: Metrics concerning the graph structure of the ontology.
metric description: Ontologies are built using triples. A triple connects two items (A and C) through a definition B. (A --B-->C). Ontologies, thus, can be seen as a kind of directed graph. We, thus, can apply measurements that assess the properties of graphs.

Hidden GCI Gount
type: Class
subclass of: Special Metrics
subclass of: Restriction
  on property: implementedBy
  has value: hiddengciCount
metric definition: Counts the number of implicit, hidden general concept inclusions (GCIs).
metric description: A hidden GCI is the combination of a named subClass relationship and an anonymous, complex class in the equivalent section. (e.g., A subClassOf B, A equivalentTo some p)

Inconsistent Classes
type: Class
subclass of: Special Metrics
subclass of: Restriction
  on property: implementedBy
  has value: inconsistentClasses
metric definition: Counts the subClasses of owl:Nothing. Requires selected reasoner.
metric description: If the reasoner detects classes that are unsatisfiable, it makes them a subclass of owl:Nothing. This metric counts all these subclasses that logically inconsistent.

Individuals
type: Class
subclass of: Instances Metrics
subclass of: Restriction
  on property: implementedBy
  has value: individuals
metric definition: Counts the number of Individuals overall.
metric description: Individuals are instantiations of things. In Opposite to e.g., programming languages, they do not need to be connected to a class. This metric counts the number of overall declared individuals.

Instance Assertions on Class
type: Class
subclass of: Class Metrics
metric definition: Counts the number of instance assertions
metric description: An instance assertion is an instanciation of an actual object. In the context of ontologies, it is an individual that is from a type of a specific class. This measurement shows the number of instances that a specific class has.

Instances Metrics
type: Class
subclass of: Elemental Metrics
metric description: The "instances Metrics" are concerned with the actual instance representation (or also "individuals") of an ontology

Inverse Object Properties
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: inverseObjectPropertyAxioms
metric definition: Counts the number of inverse object property declarations.
metric description: An inverse relation is the opposite directed relationship. If A ---->B, then the inverse of this relation is B--2-->A. An example is the relation "isFatherOf" as the inverse of "hasFather".

Inversefunctional Object Properties
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: inverseFunctionalObjectPropertyAxioms
metric definition: Counts the number of object properties that are "inverse functional"
metric description: if a relation is inverse functional x->y, then an y can have at most one x. An example is the relation isFatherOf. Then a father can have more than one child, but a child can have not more than one father.

Irreflexive Object Properties
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: irreflexiveObjectPropertyAxioms
metric definition: Counts the number of object properties that are "irreflexive".
metric description: If an object property is irreflexive, then no property can be connected to itself. Married to is an example, as no one can be married to themselves.

Iterative Metrics
type: Class
subclass of: Elemental Metrics
metric description: This group of metrics are concerned not with the ontology overall, but specific elements within the ontology (e.g., metrics for every class or relation). They are not yet implemented in the calculation engine!

Leaf Classes
type: Class
subclass of: Leaf Metrics
subclass of: Restriction
  on property: implementedBy
  has value: absoluteLeafCardinality
metric definition: Number of Classes without subclasses

Leaf Metrics
type: Class
subclass of: Graph Metrics
metric description: Leaf classes are classes that do not have further subclasses, thus are at the end of the inheritance tree.

Logical Axiom Count
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: logicalAxioms
metric definition: Counts the non-annotative axioms.
metric description: Counts all axioms that encapsulate formal meaning in the ontology. This comprises all axioms except for such used for annotative purposes (e.g., Annotation Properties and Annotation Property Assertions) or declaration axioms

Max Path Length
type: Class
subclass of: Path Metrics
metric description: The longest Path from root to a leaf class.

Maximum Breath
type: Class
subclass of: Breath Metrics
subclass of: Restriction
  on property: implementedBy
  has value: maximalBreadth
metric definition: The maximum number of siblings on a graph
metric description: Counts the maximum number of siblings of the different depth levels.

Maximum Depth
type: Class
subclass of: Depth Metrics
subclass of: Restriction
  on property: implementedBy
  has value: maximalDepth
metric definition: The maximum depth of a path in a graph.
metric description: The maximum number of following sub class statements (without regarding multi inheritance) of a path. Imagine a tree, the leaf that is the farthest away from the root.

Maximum Subclasses of a Class
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: maxSubClassesOfAClass
metric definition: The max number of subclasses, that a class in the ontology has.
metric interpretation: Shows whether there is an outlier in the ontology regarding declared the declared sub class statements

Maximum Superclasses of a Class
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: maxSuperClassesOfAClass
metric definition: Shows the maximum number of superclasses a class has.
metric description: This element indicates the highest level of multi inheritance of a class in the ontology.

Minimum Breath
type: Class
subclass of: Breath Metrics
subclass of: Restriction
  on property: implementedBy
  has value: minimumBreath
metric definition: The minimum number of siblings on a graph.
metric description: Counts the minimum number of siblings of the different depth levels.

Minimum Depth
type: Class
subclass of: Depth Metrics
subclass of: Restriction
  on property: implementedBy
  has value: minimumDepth
metric definition: The minimum depth of a path in a graph.
metric description: The minimum number of following sub class statements (without regarding multi inheritance) of a path. Imagine a tree, the leaf that is the nearest from the root.

Negative Data Property Assertions
type: Class
subclass of: Instances Metrics
subclass of: Restriction
  on property: implementedBy
  has value: negativeDataPropertyAssertionAxioms
metric definition: Counts the number of negative data property assertions.
metric description: Negative property assertions state that an individual (or instance) does not have a specific value. E.g., Maggie is not 4 years old.

Negative Object Property Assertions
type: Class
subclass of: Instances Metrics
subclass of: Restriction
  on property: implementedBy
  has value: negativeObjectPropertyAssertionAxioms
metric definition: Counts how many object properties are negatively asserted overall.
metric description: A negative object property assertion is the statement that two individuals are NOT connected with each other.

Number of Cycles
type: Class
subclass of: Graph Metrics
subclass of: Restriction
  on property: implementedBy
  has value: circleHierachies
metric definition: The number of cyclic subClass relationships
metric description: Cycles are subclass relationships like A subClassOf B; B subClassOf C, C subClassOf A. This metrics counts the number of existing cycles.
metric interpretation: Cycles are ususally bad ontology design. Please note that the occurence of cycles in the ontology prevents a lot of further calculations (e.g., how to measure depth of there are cyclic sub class relationships. Further, most reasoners cannot work with cycles in the ontology, thus detecting (rightfully so) inconsistencies.

Annotation Richness
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Restriction
      on property: sum
      all values from: Class
        intersection of: Annotation Assertions
        intersection of: Annotations On Ontology
metric definition: Mean number of annotations per class.
metric interpretation: Best: x>0.8. Worst: x<0.2

Attribute Richness
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Restriction
      on property: sum
      all values from: Class
        intersection of: Data Property Domain Declarations
        intersection of: Object Property Domain Declarations
metric definition: Mean number of attributes per class.
metric interpretation: Best: x>0.8. Worst: x<0.2

OQuaRE Adapability
type: Class
subclass of: OQuaRE Transferability
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Coupling between Objects
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Depth of subsumption hierarchy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Response for a class
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Weighted method count
metric definition: The degree to which The ontology can be adapted for different specified environments (languages, expresivity levels) without applying actions or means other than those provided for this purpose for the Ontology considered.

OQuaRE Analysability
type: Class
subclass of: OQuaRE Maintainability
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Coupling between Objects
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Depth of subsumption hierarchy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Lack of cohesion in methods
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of properties
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Response for a class
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Weighted method count
metric definition: The degree to which The ontology can be diagnosed for deficiencies or causes of failures (inconsistences), or for the parts to be modified to be identified.

OQuaRE Appropriateness Recognisability
type: Class
subclass of: OQuaRE Operability
metric definition: The degree to which the Ontology enables users to recognise whether it is appropriate for their needs.
metric description: The ability to recognise the appropriateness of the functions from initial impressions of the ontology and/or any associated documentation such as Manuals, guides, comments.

Coupling between Objects
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Class
      intersection of: Restriction
        on property: minuend
        all values from: Classes (Class Count)
      intersection of: Restriction
        on property: subtrahend
        all values from: Subclasses of Thing
  intersection of: Restriction
    on property: numerator
    all values from: Super Classes
metric definition: Coupling between Objects: Number of related classes. It is the average number of the direct parents per class minus the relationships of Thing.
metric interpretation: Best: x:1-3. Worst: x>12

Coupling between Objects 2
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Super Classes
metric interpretation: Best: x:1-3. Worst: x>12

Class Richness
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Class Assertions
metric interpretation: Best: x>0.8. Worst: x<0.2

OQuaRE Changeability
type: Class
subclass of: OQuaRE Maintainability
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Coupling between Objects
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Depth of subsumption hierarchy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Lack of cohesion in methods
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of children
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of properties
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Response for a class
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Weighted method count
metric definition: The degree to which The Ontology enables a specified modification to be implemented. The ease with which a The ontology can be modified.

OQuaRE Classifying Instances
type: Class
subclass of: OQuaRE Functional Adequacy
metric definition: Degree in which ontology Instances can be recognized as member of a certain class

OQuaRE Clustering
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Annotation Richness
metric definition: Degree in which the annotations of data with respect to ontology terms can be used for clustering such data against the aspects of the ontology.
metric description: Clustering can be defined as the process of organizing objects into groups whose members are more similar to each other than to individuals in other groups.

OQuaRE Comfort
type: Class
subclass of: Satisfaction in use
metric definition: physical satisfaction

OQuaRE Compatibility
type: Class
subclass of: OQuaRE Quality Dimensions
metric description: The ability of two or more software components to exchange information and/or to perform their required functions while sharing the same hardware or software environment

OQuaRE Consistency
type: Class
subclass of: OQuaRE Structural
metric definition: Degree of the consistency of the ontology
metric description: consistent naming conventions, Logical consistency, structural consistency, consistent distinction class - instance

OQuaRE Consistent Search and Query
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Annotation Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Attribute Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQuaRE Formalisation
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationships per class
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationship Richness
metric definition: The degree which the formal model and structure of the ontology provide a semantic context to evaluate which are the data wanted by the users, allowing better querying and searching methods

OQuaRE Context Conformity in Use
type: Class
subclass of: OQuaRE Usability in Use
disjoint with: OQuaRE Context extendibility in use
metric definition: The degree to which usability in use meets requirements in all the intended contexts of use

OQuaRE Context extendibility in use
type: Class
subclass of: OQuaRE Usability in Use
metric definition: The degree of usability in use in contexts beyond those initially intended

OQuaRE Controlled Vocabulary
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Annotation Richness
metric definition: Capability of the ontology to avoid heterogeneity of the terms.
metric description: The labels of the ontological entities are used to avoid heterogeneity, which would complicate data processing and analysis. Ontologies provide terminology management, unifying the terms used for referring to the included knowledge entities which should have an unambiguous and non-redundant definition. ontological concepts are described with different terminologies, different meanings are assigned to the same word in different contexts and different taxonomies are examples of synonymy, polysemy and structural heterogeneity

OQuaRE Cycles
type: Class
subclass of: OQuaRE Structural
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: Number of Cycles
metric definition: The existence of cycles through a particular semantic relation is usually a sign of bad design, since they may lead to inconsistencies.

Depth of subsumption hierarchy
type: Class
subclass of: OQuaRE Metrics
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Maximum Depth
metric definition: Depth of subsumption hierarchy: Length of the largest path from Thing to a leaf class.
metric interpretation: Best: x:1-2. Worst: x>8

OQuaRE Decision Trees
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Attribute Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationships per class
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Tangledness
metric definition: Decision trees are used to represent the logical structures of classification rules for domain specific empirical data.
metric description: Capability of the ontology to be used building Decision trees.

OQuaRE Ease of Use
type: Class
subclass of: OQuaRE Operability
metric definition: The degree to which the ontology makes it easy for users to operate and control it.

OQuaRE Effectiveness in Use
type: Class
subclass of: OQuaRE Flexibility in Use
metric definition: The degree to which specified users expend appropriate amounts of resources in relation to the effectiveness achieved in a specified context of use

OQuaRE Efficiency in Use
type: Class
subclass of: OQuaRE Flexibility in Use
metric definition: The degree to which specified users can achieve specified goals with accuracy and completeness in a specified context of use.

OQuaRE Formal Relations Support
type: Class
subclass of: OQuaRE Structural
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationship Richness
metric definition: Capability of the ontology to represent relations supported for formal theories different to the formal support for taxonomy
metric description: It accounts for the types of formal relations supported by the ontology, different to part-of relations

OQuaRE Formalisation
type: Class
subclass of: OQuaRE Structural
metric definition: Capability of the ontology to support reasoning
metric description: An ontology should be expressed in a common formal language E.g. for biontologies in agree with the ontology principle FP 002 format : OBO Format, OWL or OWL2 concrete syntax, RDF/XML, OWL2-XML, OWL2-Manchester Syntax, Common Logic concrete syntax, CLIF, Conceptual Graphs, etc

OQuaRE Functional Adequacy
type: Class
subclass of: OQuaRE Quality Dimensions
metric description: The capability of the ontologies to provide concrete functions.

OQuaRE Guidance
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Attribute Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationships per class
metric definition: Capability of the ontology to guide the specification of domain theories.
metric description: Ontology by capturing knowledge about a domain and encapsulating constraints about class membership provides guidance in the specification of domain theories and support decision making processes.

OQuaRE Helpfulness
type: Class
subclass of: OQuaRE Operability
metric definition: The degree to which the Ontology provides help when users need assistance.
metric description: The ontology provide clear error messages, manuals and guides for help the users, including help comprehensive, effective and easy to find.

Relationships per class
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Sub Class Declarations
metric interpretation: Best: x>0.8. Worst: x<0.2

OQuaRE Indexing and Linking
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Attribute Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationships per class
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationship Richness
metric definition: Degree in which the classes defined in the ontology can act as indexes for quick information retrieval

OQuaRE Inference
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Class Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQuaRE Formalisation
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationship Richness
metric definition: The degree to which The formal model of the ontology can be used by reasoners to make implicit knowledge explicit.
metric description: Inference expands the knowledge base with additional information using the existing data, metadata, and rules.

OQuaRE Interoperability
type: Class
subclass of: OQuaRE Compatibility
metric definition: The degree to which the ontology can be cooperatively operable combining its knowledge with one or more other ontologies.
metric description: Ontology matching consists of matching a concept from one ontology to another.

OQuaRE Knowledge Reuse
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Annotation Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Attribute Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQuaRE Consistency
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQuaRE Formalisation
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationships per class
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Lack of cohesion in methods
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of properties
metric definition: The degree to which The ontology knowledge can be used to build other ontologies.

Lack of cohesion in methods
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Path Length To Leaf Classes
  intersection of: Restriction
    on property: numerator
    all values from: Paths Overall
metric description: The semantic and conceptual relatedness of classes can be used to measure the separation of responsibilities and independence of components of ontologies.
metric interpretation: Best: x:1-2. Worst: x>8

OQuaRE Learnability
type: Class
subclass of: OQuaRE Operability
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Coupling between Objects
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Lack of cohesion in methods
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of children
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of properties
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Response for a class
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Weighted method count
metric definition: The degree to which the ontology enables users to learn its application.
metric description: Effectiveness of the user documentation and/or help system.

OQuaRE Likability
type: Class
subclass of: Satisfaction in use
metric definition: cognitive satisfaction

OQuaRE Maintainability
type: Class
subclass of: OQuaRE Quality Dimensions
metric description: The capability of ontologies to be modified for changes in environments, in requirements or in functional specifications.

OQuaRE Metrics
type: Class
subclass of: Quality Frameworks
see also: Reiz, A. and Sandkuhl, K. (2022). Harmonizing the OQuaRE Quality Framework. In Proceedings of the 24th International Conference on Enterprise Information Systems - Volume 2, ISBN 978-989-758-569-2. ISSN 2184-4992, pages 148-158. Duque-Ramos, Astrid; Fernández-Breis, J. T.; Stevens, R.; Aussenac-Gilles, Nathalie (2011): OQuaRE: A square-based approach for evaluating the quality of ontologies. In Journal of Research and Practice in Information Technology 43 (2), pp. 159–176.

OQuaRE Modification Stability
type: Class
subclass of: OQuaRE Maintainability
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Coupling between Objects
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of children
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of properties
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Response for a class
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Weighted method count
metric definition: The degree to which The ontology can avoid unexpected effects from modifications of the software or knowledge.

OQuaRE Modularity
type: Class
subclass of: OQuaRE Maintainability
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Coupling between Objects
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Weighted method count
metric definition: The degree to which the ontology is composed of discrete components such that a change to one component has minimal impact on other components.

Number of ancestor classes
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Leaf Classes
  intersection of: Restriction
    on property: numerator
    all values from: Super Classes of Leaf Classes
metric definition: Number of Ancestor Classes: Mean number of ancestor classes per leaf class. It is the number of direct superclasses per leaf class.
metric interpretation: Best: x:1-2. Worst: x>8

Number of children
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Class
      intersection of: Restriction
        on property: minuend
        all values from: Classes (Class Count)
      intersection of: Restriction
        on property: subtrahend
        all values from: Subclasses of Thing
  intersection of: Restriction
    on property: numerator
    all values from: Sub Class Declarations
metric definition: Number of Children: Mean number of direct subclasses. It is the number of relationships divided by the number of classes minus the relationships of Thing.
metric interpretation: Best: x:1-2. Worst: x>8

Number of properties
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Restriction
      on property: sum
      all values from: Class
        intersection of: Data Property Assertions
        intersection of: Object Property Class Assertion
metric definition: Number of properties: Number of properties per class.
metric interpretation: Best: x:1-2. Worst: x>8

OQuaRE Operability
type: Class
subclass of: OQuaRE Quality Dimensions
metric description: Effort needed for use, and on the individual assessment of such use, by a stated or implied set of users.

Ancestors per class
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Super Classes
metric interpretation: Best: x>0.8. Worst: x<0.2

Properties Richness
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Restriction
      on property: sum
      all values from: Class
        intersection of: Data Property Assertions
        intersection of: Object Property Class Assertion
        intersection of: Sub Class Declarations
  intersection of: Restriction
    on property: numerator
    all values from: Sub Class Declarations
metric interpretation: Best: x>0.8. Worst: x<0.2

OQuaRE Pleasure
type: Class
subclass of: Satisfaction in use
metric definition: emotional satisfaction

OQuaRE Portability
type: Class
subclass of: OQuaRE Transferability
metric definition: The degree in which an Ontology or one part of the ontology can be transferred from one hardware or software environment to another
metric description: The degree to which The ontology can be translated between different formal languages, or how easily the code can be moved to another language

OQuaRE Precision
type: Class
subclass of: OQuaRE Functional Adequacy
metric description: The degree to which The ontology provides the right or specified results with the needed degree of accuracy

OQuaRE Quality in use
type: Class
subclass of: OQuaRE Quality Dimensions
metric description: Quality in a particular context of use. Quality in use is the degree to which a product used by specific users meets their needs to achieve specific goals

Response for a class
type: Class
subclass of: OQuaRE Metrics
subclass of: Restriction
  on property: multiplication
  all values from: Class
    intersection of: Class
      intersection of: Restriction
        on property: divisor
        all values from: Class
      intersection of: Restriction
        on property: numerator
        all values from: Sub Class Declarations
    intersection of: Restriction
      on property: sum
      all values from: Class
        intersection of: Data Property Assertions
        intersection of: Object Property Class Assertion
metric definition: Response for a class: Number of properties that can be directly accessed from the class.
metric interpretation: Best: x:1-3. Worst: x>12

Relationship Richness
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Restriction
      on property: sum
      all values from: Class
        intersection of: Data Property Assertions
        intersection of: Object Property Class Assertion
        intersection of: Sub Class Declarations
  intersection of: Restriction
    on property: numerator
    all values from: Restriction
      on property: sum
      all values from: Class
        intersection of: Data Property Assertions
        intersection of: Object Property Class Assertion
metric definition: Relationship Richness: Number of properties defined in the ontology divided by the number of relationships and properties
metric interpretation: Best: x>0.8. Worst: x<0.2

OQuaRE Redundancy
type: Class
subclass of: OQuaRE Structural
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Annotation Richness
metric definition: Capability of the ontology to be informative
metric description: Some redundancy types are: Inferred information more than once from the relations, classes and instances found in ontology The same/different formal definition of classes, properties or instances referring to different/same classes, properties or instances

OQuaRE Reference Ontology
type: Class
subclass of: OQuaRE Functional Adequacy
metric definition: Degree in which the ontology can be used as a reference resource for the particular domain the ontology is built for.
metric description: Machines can exploit better the reference knowledge offered by an ontology which have a more explicit structure

OQuaRE Replaceability
type: Class
subclass of: OQuaRE Compatibility
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Depth of subsumption hierarchy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of children
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of properties
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Weighted method count
metric definition: The degree to which The ontology can be used in place of another specified Ontology for the same purpose in the same environment.

OQuaRE Results Representation
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Attribute Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Class Richness
metric definition: Capability of the ontology to analize complex results such as microarrays experiments

OQuaRE Reusability
type: Class
subclass of: OQuaRE Maintainability
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: Number of children
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Coupling between Objects
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Depth of subsumption hierarchy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of properties
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Response for a class
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Weighted method count
metric definition: The degree to which an asset (part of) the ontology can be used in more than one ontology, or in building other assets.

OQuaRE Schema and Value Reconciliation
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Attribute Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQuaRE Consistency
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQuaRE Formalisation
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationship Richness
metric definition: Degree in which ontology provide a common data model that can be applied to reconciliation and integration.
metric description: Integration is building a new ontology reusing other available ontologies. Different ontologies with subjective features and particular perspective on the world, cannot be compared without reconciliation and integration, which are necessary to interchange, migration and standardization of information and knowledge of such ontologies

OQuaRE Similarity
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Attribute Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationship Richness
metric definition: Capability of the component of the ontology to be compared for similarity
metric description: There exist different similarity measures: Taxonomy similarity, Relation similarity, Attribute similarity, semantic similarity.

OQuaRE Structural
type: Class
subclass of: OQuaRE Quality Dimensions
metric description: This category is the only one in this framework that is not specified as such in SQuaRE, but it is important when evaluating ontologies, since it accounts for ontology quality factors such as consistency, formalisation, redundancy or tangledness

OQuaRE Structural Accuracy
type: Class
subclass of: OQuaRE Structural
metric description: Correctness of taxonomic links, use of upper level with disjoint categories, consideration of "all some rule" in case of existential Restrictions, value restrictions only if disjoint partitions available, domain and range restrictions of object properties, sufficient metadata and annotation properties, free text definitions where necessary
metric description: Degree of the correctness of the terms used in the ontology

Tangledness
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Super Classes
metric definition: Mean number of parents per class.
metric interpretation: Best: x:1-2. Worst: x>8

Tangledness 2
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes with Multiple Inheritance
  intersection of: Restriction
    on property: numerator
    all values from: Superclasses of Classes with Multiple Inheritance
metric interpretation: Best: x:1-2. Worst: x>8

OQuaRE Tangledness
type: Class
subclass of: OQuaRE Structural
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Tangledness
metric definition: This measures the distribution of multiple parent categories, so that it is related to the existence of multiple inheritance.

OQuaRE Testability
type: Class
subclass of: OQuaRE Maintainability
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Coupling between Objects
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Depth of subsumption hierarchy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of properties
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Response for a class
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Weighted method count
metric definition: The degree to which the ontology modified can be validated.

OQuaRE Text Analysis
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQuaRE Formalisation
metric definition: Capability of the structure of the ontology to helps detecting associations between words or concepts and classifying word types.

OQuaRE Transferability
type: Class
subclass of: OQuaRE Quality Dimensions
metric description: The degree to which the software product can be transferred from one environment to another

Weighted method count
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Restriction
      on property: sum
      all values from: Class
        intersection of: Data Property Assertions
        intersection of: Object Property Class Assertion
        intersection of: Sub Class Declarations
metric definition: Weighted Method Count: Mean number of properties and relationships per class.
metric interpretation: Best: x:1-2. Worst: x>8

Weighted method count 2
type: Class
subclass of: OQuaRE Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Leaf Classes
  intersection of: Restriction
    on property: numerator
    all values from: Paths Overall
metric interpretation: Best: x:1-2. Worst: x>8

OQual Anonymous classes ratio
type: Class
subclass of: OQual Measures for logical adequacy
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Anonymous Classes
metric definition: The cardinality of the set of anonymous classes divided by the cardinality of the set of (class) nodes.

OQual Average Sibling Fan-Outness Without Metric Space
type: Class
subclass of: OQual Measures for Fan-Outness
metric interpretation: meaningful only when metric values or lists of values are represented as classes. For metric spaces this is rarely practiced, specially becaue languages like OWL have separate domains for datatypes.

OQual Average sibling fan-outness without lists of values
type: Class
subclass of: OQual Measures for Fan-Outness
metric interpretation: meaningful only when metric values or lists of values are represented as classes. For metric spaces this is rarely practiced, specially becaue languages like OWL have separate domains for datatypes.

OQual Axiom-class ratio
type: Class
subclass of: OQual Measures for logical adequacy
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Axioms
metric definition: The cardinality of the set of classes represents by nodes in g divided by the cardinality of the set of axioms represented by subgraphs in g.

OQual Cognitive Ergonomics
type: Class
subclass of: OQual Quality Dimensions
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: OQual Anonymous classes ratio
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: OQual Measures for Breath
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: OQual Measures for Depth
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: OQual Tangledness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Class relation ratio
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Measures for density
metric description: This principle prospects an ontology that can be easily understood, manipulated, and exploited.

OQual Compliance to Expertise
type: Class
subclass of: OQual Quality Dimensions
metric description: this principle prospects an ontology that is compliant to one or more users.

OQual Compliance to procedures for mapping extension integration adaptation
type: Class
subclass of: OQual Quality Dimensions
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: OQual Tangledness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Measures for modularity
metric description: this principle prospects an ontology that can be easily understood and manipulated for reuse and adaptation.

OQual Computational Integrity and Effiency
type: Class
subclass of: OQual Quality Dimensions
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: OQual Class relation ratio
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: OQual Cycle Ratio
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: OQual Tangledness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Consistency ratio
metric description: this principle prospects an ontology that can be successfully/easily processed by a reasoner (inference engine, classifier, etc.).

OQual Flexible Intuition
type: Class
subclass of: OQual Quality Dimensions
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Measures for density
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Measures for modularity
metric description: This principle prospects an ontology that can be easily adapted to multiple views

OQual Generic Acessibility
type: Class
subclass of: OQual Quality Dimensions
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: OQual Generic complexity
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Measures for modularity
metric description: This principle prospects an ontology that can be easily accessed for effective application.

OQual Generic complexity
type: Class
subclass of: OQual Measures for logical adequacy
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Computational Complexity
metric description: a complexity scale, e.g. the one used for description logics

OQual Individual-Class ratio
type: Class
subclass of: OQual Measures for logical adequacy
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Instances Metrics
metric definition: The cardinality of the set of classes represents by nodes in g divided by the cardinality of the set of individuals represented by special nodes in g.

OQual Measures for Breath
type: Class
subclass of: OQual Structural
metric definition: Breadth is a property related to the cardinality of levels (generations) in a graph, where the arcs considered here are again only isa arcs. This measure only applies to digraphs.

OQual Measures for Depth
type: Class
subclass of: OQual Structural
metric definition: Depth is a graph property related to the cardinality of paths in a graph, where the arcs considered here are only isa arcs. This measure type only applies to digraphs (directed graphs).

OQual Measures for differentia specifica
type: Class
subclass of: OQual Structural
metric description: related to the “rationale” behind sibling node sets. The rationale behind a sibling node set can be measured by looking for arcs that do not represent isa relationships, and are shared by all siblings in the set (these arcs represent a common relational property). For a more relevant measure, we exclude from this measure the sibling nodes that represent values from a metric space of just a list

OQual Measures for meta-logical adequacy
type: Class
subclass of: OQual Structural
metric description: Formal semantics can go beyond first-order, in order to attempt at representing functional adequacy as well. The major example of that attempt is OntoClean [Guarino&Welty 2004]. OntoClean aims to classify the classes of an ontology according to some meta-properties, e.g. rigidity, unity, dependence. OntoClean metaproperties try to reduce some functional measures to the measurement of adequacy w.r.t. series of possible worlds (states of affairs). Possible worlds can be used to check the quality of an ontology only in an ex-post way, e.g. by analyzing the history of a temporal database built according to the ontology that must be evaluated. This is unfit, since an ontology is supposed to be evaluated before its application, not afterwords. For this reason, OntoClean methodology suggests designers or experts to assign metaproperties in advance, and then to use these assignments to check the meta-logical consistency of the taxonomy.

OQual Meta Level Integrity
type: Class
subclass of: OQual Quality Dimensions
subclass of: Restriction
  on property: negativeAffectedBy
  some values from: OQual Tangledness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Meta-consistency ratio
metric description: This principle prospects an ontology that respects certain ordering criteria that are assumed as quality indicators

OQual Modularity rate
type: Class
subclass of: OQual Measures for modularity
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Connected Graphs
metric definition: A module is any subgraph sg of a graph g, where the set of graph elements S’ for sg is such that S’ ⊆ S. Two modules sg1 and sg2 are disjoint when only ≥0 isa arcs ai connect sg1 to sg2, and each ai has the same direction. Modularity is related to the asserted modules of a graph, where the arcs considered here are either isa or non-isa arcs. We distinguish the following modularity measures. The set of modules from a graph g is called here M. m = n_m / n_s where n_m is the cardinality of M and n_s is the cardinalty of S( The set of graph elements)

OQual Organizational Fitness
type: Class
subclass of: OQual Quality Dimensions
metric description: This principle prospects an ontology that can be easily deployed within an organization, and that has a good coverage for that context.

OQual Structural
type: Class
subclass of: Quality Frameworks
see also: Gangemi, Aldo; Catenacci, Carola; Ciaramita, Massimiliano; Lehmann, Jos; Gil, Rosa; Bolici, Francesco; Strignano Onofrio (2005): Ontology evaluation and validation. An integrated formal model for the quality diagnostic task.

OQual Transparency
type: Class
subclass of: OQual Quality Dimensions
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Anonymous classes ratio
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Axiom-class ratio
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Generic complexity
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Measures for degree distribution
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Measures for density
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Measures for differentia specifica
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Measures for modularity
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: OQual Modularity rate
metric description: This principle prospects an ontology that can be analyzed in detail, with a rich formalization of conceptual choices and motivations

OQual Weighted Ratio Of Sibling Fan-Outness
type: Class
subclass of: OQual Measures for Fan-Outness
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Total Depth
  intersection of: Restriction
    on property: numerator
    all values from: Sub Class Declarations
metric interpretation: meaningful only when metric values or lists of values are represented as classes. For metric spaces this is rarely practiced, specially becaue languages like OWL have separate domains for datatypes.

OQual Weighted Ratio of Leaf Fan-Outness
type: Class
subclass of: OQual Measures for Fan-Outness
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Total Depth
  intersection of: Restriction
    on property: numerator
    all values from: Leaf Classes
metric interpretation: meaningful only when metric values or lists of values are represented as classes. For metric spaces this is rarely practiced, specially becaue languages like OWL have separate domains for datatypes.

Object Properties
type: Class
subclass of: Property Metrics
subclass of: Restriction
  on property: implementedBy
  has value: objectProperties
metric definition: Number of declared Object Properties
metric description: Measures the number of declared object properties (also such, that are implicit stated). Is different from the object property assertion.

Object Property Assertions
type: Class
subclass of: Instances Metrics
subclass of: Restriction
  on property: implementedBy
  has value: objectPropertyAssertionaxioms
metric definition: Counts how many object properties are asserted overall.
metric description: An object property assertion is the statement that two individuals are connected with each other.

Object Property Characteristics
type: Class
subclass of: Property Metrics
metric description: Object properties can be further logically described usiing predefined attributes (like disjointness, equivalence). These statements are covered by this category.

Object Property Class Assertion
type: Class
subclass of: Property Metrics
subclass of: Restriction
  on property: implementedBy
  has value: objectPropertiesOnClasses
metric definition: Number of declared Object Properties on Classes
metric description: Classes can be connected using object properties in SubClassOf relations. This metric measures, how often that is the case.

Object Property Domain Declarations
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: objectPropertyDomainAxioms
metric definition: Counts the number of object property domain axioms.
metric description: The "domain" restriction limits the available classes from where a relation starts. If a relation is A->B, then the domain limits what classes A can be. (E.g., isParent has the domain "Person")

Object Property Instance Assertion
type: Class
subclass of: Property Metrics
metric definition: Number of Object Properties on Individuals
metric description: Measures how often individuals are connected using object properties.

Object Property Range Declarations
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: objectPropertyRangeAxioms
metric definition: Counts the number of object property range axioms.
metric description: The "Range" restriction limits the available classes to where a relation ends. If a relation is A->B, then the domain limits what classes "B" can be. (E.g., isParentOf has the range "Child")

OntoQA
type: Class
subclass of: Quality Frameworks
see also: Tartir, Samir; Arpinar, I. Budak (2007): Ontology Evaluation and Ranking using OntoQA. In : International Conference on Semantic Computing, 2007. ICSC 2007 ; 17 - 19 Sept. 2007, Irvine, California ; proceedings ; [held in conjunction with] the First International Workshop on Semantic Computing and Multimedia Systems (IEEE-SCMS 2007). International Conference on Semantic Computing (ICSC 2007). Irvine, CA, USA, 9/17/2007 - 9/19/2007. IEEE Computer Society; IEEE International Conference on Semantic Computing; ICSC; International Workshop on Semantic Computing and Multimedia Systems; IEEE-SCMS. Los Alamitos, Calif.: IEEE Computer Society, pp. 185–192.
see also: Tartir, Samir; Arpinar, I. Budak; Moore, Michael; Sheth, Amit P.; Aleman-Meza, Boanerges (2005): OntoQA: Metric-Based Ontology Quality Analysis. In : IEEE Workshop on Knowledge Acquisition from Distributed, Autonomous, Semantically Heterogeneous Data and Knowledge Sources. Houston, 11/27/2005.

OntoQA Attribute Richness
type: Class
subclass of: OntoQA Schema Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Restriction
      on property: sum
      all values from: Class
        intersection of: Data Properties
        intersection of: Object Properties
metric definition: Formally, the attribute richness (AR) is defined as the average number of attributes (slots) per class. It is computed as the number attributes for all classes (att) divided by the number of classes (C).
metric description: The number of attributes (slots) that are defined for each class can indicate both the quality of ontology design and the amount of information pertaining to instance data. In general we assume that the more slots that are defined the more knowledge the ontology conveys.
metric interpretation: The result will be a real number representing the average number of attributes per class, which gives insight into how much knowledge about classes is in the schema. An ontology with a high value for the AR indicates that each class has a high number of attributes on the average, while a lower value might indicate that less information is provided about each class.

OntoQA Average Population
type: Class
subclass of: OntoQA Knowledgebase Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Individuals
metric definition: Formally, the average population (P) of classes in a KB is defined as the number of instances of the KB (I) divided by the number of classes defined in the ontology schema (C). P = I / C
metric description: (average distribution of instances across all classes): This measure is an indication of the number of instances compared to the number of classes. It can be useful if the ontology developer is not sure if enough instances were extracted compared to the number of classes.
metric interpretation: The result will be a real number that shows how well is the data extraction process that was performed to populate the KB. For example, if the average number of instances per class is low, when read in conjunction with the previous metric, this number would indicate that the instances extracted into the KB might be insufficient to represent all of the knowledge in the schema. Keep in mind that some of the schema classes might have a very low number or a very high number by the nature of what it is representing.

OntoQA ClassInstance Distribution
type: Class
subclass of: OntoQA Knowledgebase Metrics
subclass of: Restriction
  on property: standardDeviationOf
  all values from: Instance Assertions on Class
metric definition: The class instance distribution of an ontology is defined as the standard deviation in the number of instances per class.
metric description: This metric is also useful to evaluate the instance extraction process. It provides an indication on how instances are spread across the classes of the schema. It can be used to discover problems in the instance extraction process.

OntoQA Class Connectivity
type: Class
subclass of: OntoQA Class Metrics
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Instance Assertions on Class
metric definition: The connectivity of a class (Conn(Ci)) is defined as the total number of relationships instances of the class have with instances of other classes. Conn(Ci) = |NIREL(Ci)|
metric description: This metric gives an indication of the centrality of a class. With the importance metric mentioned below, both metrics provide a better understanding of how focal some classes are in the KB, which might be help in cases where a user has two ontologies with the similar classes defined in their schemas, but classes that are be important to the user play a central role in one of them, while being on the boundary in the other.
metric interpretation: The result of the formula will be an integer apresenting the popularity of instances of the class. A class with a high Cn plays a central role in the ontology compared to a class with a lower value. This measure can be used to understand the nature of the ontology by indicating which classes play a central role compared to other classes.

OntoQA Class Fullness
type: Class
subclass of: OntoQA Class Metrics
metric definition: Formally, the fullness (F) of a class Ci is defined as the actual number of instances that belong to the subtree rooted at Ci (Ci(I)) compared to the expected number of instances that belong to the subtree rooted at Ci (Ci`(I)). F = Ci(I) / Ci`(I)
metric description: This metric details the KB average population metric mentioned above. It would be mainly used by an ontology developer interested in knowing how well the data extraction was with respect to the expected number of instances of each class. This is helpful in directing the extraction process to any resources that will add instances belonging to classes that are not full.
metric interpretation: The result of the formula will be a percentage representing the actual coverage of instances compared to the expected coverage. In most cases, this measure is an indication of how well the instance extraction process performed. For example, a KB where most classes have a low F would require more data extraction. On the other hand, a KB where most classes are almost full would indicate that it reflects more closely the knowledge encoded in the schema.

OntoQA Class Importance
type: Class
subclass of: OntoQA Class Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Instances Metrics
  intersection of: Restriction
    on property: numerator
    all values from: Instance Assertions on Class
metric definition: The importance of a class (Imp(Ci)) is defined as the number of instances that belong to the inheritance subtree rooted at Ci in the KB(inst(Ci)) compared to the total number of class instances in the KB (CI). Imp(Ci) = Inst(Ci)/KB(CI)
metric description: This metric is important because it helps in identifying which areas of the schema are in focus when the instances are extracted and inform the user of the suitability of his/her intended use. It will also help direct the ontology developer or data extractor to where s/he should focus on getting data if the intention is to get a consistent coverage of all classes in the schema. Although this measure does not consider the real world semantics, where some classes naturally have more instances than others, the class importance can still be used (together with the class connectivity measure mentioned above) to give an indication on what parts of the ontology are considered focal and what parts are on the edges.

OntoQA Class Inheritance Richness
type: Class
subclass of: OntoQA Schema Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Sub Class Declarations
metric definition: Formally, the inheritance richness of class Ci is defined as the average number of subclasses per class in the subtree. The number of subclasses for a class Ci is defined as Hc (Cl,Ci) and the number of nodes in the subtree is C'l.
metric description: This measure details the schema IRS metric mentioned above and describes the distribution of information in the current class subtree per class. This measure is a good indication of how well knowledge is grouped into different categoreis and subcategories under this class.
metric interpretation: The result of the formula will be a real number representing the average number of classes per schema level. The interpretation of the results of this metric depends highly on the nature of the ontology. Classes in an ontology that represents a very specific domain will have low IRC values, while classes in an ontology that represents a wide domain will usually have higher IRC values.

OntoQA Class Metrics
type: Class
subclass of: OntoQA Instance Metrics
metric description: This group of metrics indicates how each class defined in the ontology schema is being utilized in the KB.

OntoQA Class Readability
type: Class
subclass of: OntoQA Class Metrics
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Annotations on Class
metric definition: Formally, the readability (Rd) of a class Ci is defined as the sum of the number attributes that are comments and the number of attributes that are labels the class has.
metric description: This metric indicates the existence of human readable descriptions in the ontology, such as comments, labels, or captions. This metric can be a good indication if the ontology is going to be queried and the results listed to users.
metric interpretation: The result of the formula will be an integer representing the availability of human-readable information for the instances of the current class.

OntoQA Class Relationship Richness
type: Class
subclass of: OntoQA Class Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Definied Relationships on Class
  intersection of: Restriction
    on property: numerator
    all values from: Relationship Assertions on Class
metric definition: Formally, the relationship richness (RR) of a class Ci is defined as the number of relationships that are being used by instances Ii that belong to Ci (P(Ii,Ij)) compared to the number of relationships that are defined for Ci at the schema level (P(Ci,Cj)) RRc = (P(Ii, Ij), Ii eCi(I))/P(Ci, Cj)
metric description: This is an important metric reflecting how much of the properties in each class in the schema is actually being used at the instances level. It is a good indication of the how well the extraction process performed in the utilization of information defined at the schema level.
metric interpretation: The result of the formula will be a percentage representing how well the KB utilizes the knowledge defined in the schema regarding the class in focus. For example, if most classes have low RRC values, this would mean that instances are using only a few number of the class relationships in the schema in contrast to another ontology where instances have relationships that span most of the relationships available at the class level in the schema.

OntoQA Class Relationship Utiliization
type: Class
subclass of: OntoQA Class Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Definied Relationships on Class
  intersection of: Restriction
    on property: numerator
    all values from: Relationship Assertions on Class
metric definition: The relationship richness (RU) of a class Ci is defined as the number of relationships that are being used by instances Ii that belong to Ci (P(Ii,Ij)) compared to the number of relationships that are defined for Ci at the schema level (P(Ci,Cj)). RU(Ci) = IREL(Ci) / CREL(Ci)
metric description: This metric reflects how the relationships defined for each class in the schema are being used at the instances level. It is a good indication of the how well the extraction process performed in the utilization of information defined at the schema level. This metric can be used to distinguish between two ontologies having similar schemas but one of them utilizes only a few of the available relationships while other utilizes more.

OntoQA Class Utilization
type: Class
subclass of: OntoQA Knowledgebase Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Classes with Instances
metric definition: The class utilization (CU) of an ontology is defined as the ratio of the number of populated classes (C`) divided by the total number of classes defined in the ontology schema (C).
metric description: This metric reflects how classes defined in the schema are being utilized in the KB. This metric can be used to differentiate between two ontologies having the same classes defined in their schemas but one of them populates more classes than the other one, indicating a richer KB.
metric interpretation: The result will be a percentage indicating how the KB utilizes classes defined in the schema. Thus, if the KB has a very low CU, then the KB does not have data that exemplifies all the knowledge that exists in the schema. This metric will be very useful in situations where instances are being extracted into an ontology and it is needed to evaluate the results of the extraction process.

OntoQA Cohesion
type: Class
subclass of: OntoQA Knowledgebase Metrics
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Connected Graphs
metric definition: The cohesion (Coh) of an ontology is defined as the number of connected components (CC) of the graph representing the KB.
metric description: This metric represents the number of connected components in the KB. This metric can particularly help if 'islands' form in the KB as a result of extracting data from separate sources that do not have common knowledge, giving insight into what areas need more instances in order to enable the different connected components to connect to each other. Having less connected components (ideally 1) can be helpful, for example, in finding more useful semantic-associations [3] in the ontology.
metric interpretation: The result will be an integer representing the number of connected components in the ontology.

OntoQA Inheritance Richness
type: Class
subclass of: OntoQA Schema Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Sub Class Declarations
metric definition: Formally, the inheritance richness of the schema (IRs) is defined as the average number of subclasses per class.
metric description: This measure describes the distribution of information across different levels of the ontology inheritance tree or the fan-out of parent classes. This is a good indication of how well knowledge is grouped into different categories and subcategories in the ontology. This measure can distinguish a horizontal ontology from a vertical ontology or an ontology with different levels of specialization. A horizontal (or flat) ontology is an ontology that has a small number of inheritance levels, and each class has a relatively large number of subclasses. In contrast, a vertical ontology contains a large number of inheritance levels where classes have a small number of subclasses. This metric can be measured for the whole schema or for a subtree of the schema.
metric interpretation: The result of the formula will be a real number representing the average number of subclasses per class. An ontology with a low IRS would be or a vertical nature, which might reflect a very detailed type of knowledge that the ontology represents. while an ontology with a high IRS would be of a horizontal nature, which means that ontology represents a wide range of general knowledge.

OntoQA Instance Metrics
type: Class
subclass of: OntoQA
metric description: The way instances are placed within an ontology is also a very important aspect of ontology evaluation. The placement of instance data and distribution of the data can indicate the effectiveness of the ontology design and the amount of knowledge represented by the ontology. Instance metrics can divided on three main sub-dimensions: Overall KB (knowledgebase) metrics that evaluates the overall placement of instances with regard to the schema, class-specific metrics that evaluate the instances of a specific class and compare it to instances of other classes, and relationship-specific metrics that evaluate the instances of a specific relationship and compare it to instances of other relationships.

OntoQA Knowledgebase Metrics
type: Class
subclass of: OntoQA Instance Metrics
metric description: This group of metrics gives an overall view on how instances are represented in the KB.

OntoQA Relationship Diversity
type: Class
subclass of: OntoQA Schema Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Sub Class Declarations
  intersection of: Restriction
    on property: numerator
    all values from: Object Property Class Assertion
metric definition: The relationship diversity (RD) of a schema is defined as the ratio of the number of noninheritance relationships (P), divided by the total number of relationships defined in the schema (the sum of the number of inheritance relationships (H) and noninheritance relationships (P)). RD = P / (H +P)
metric description: This metric reflects the diversity of relationships in the ontology. An ontology that contains mostly inheritance relationships (taxonomy) usually conveys less information than an ontology that contains a diverse set of relationships. However, in some applications, users might be interestedin ontologies with mostly inheritance relationships (e.g. species classification), and OntoQA gives the user the option to specify whether she prefers a taxonomy or an ontology with diverse relationships.
metric interpretation: For example, if an ontology has an RD value close to 0 that would indicate that most of the relationships are inheritance relationships. In contrast, an ontology with a value close to 1 would indicate that most of the relationships are non-inheritance.

OntoQA Relationship Importance
type: Class
subclass of: OntoQA Relationship Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Object Property Instance Assertion
  intersection of: Restriction
    on property: numerator
    all values from: Relation Assertion on Relation
metric definition: The importance of a relationship (Imp(Ri)) is defined as the number of instances of relationship Ri in the KB (inst(Ri)) compared to the total number of property instances in the KB (RI) Imp(Ri) = Inst(Ri) / KB (RI)
metric description: Relationship Importance: This metric measures the percentage of instances of a relationship with respect to the total number of relationship instances in the KB. This metric is important in that it will help in identifying which schema relationships were in focus when the instances were extracted and inform the user of the suitability of his/her intended use. This metric can also help in directing the instance extraction process to include a more diverse set of relationships the KB does not include the required diversity.
metric interpretation: The result of the formula will be a percentage representing the importance of the current class.

OntoQA Relationship Metrics
type: Class
subclass of: OntoQA Instance Metrics
metric description: This group or metrics indicates how each relationship defined in the ontology schema is being utilized in the KB.

OntoQA Relationship Richness
type: Class
subclass of: OntoQA Schema Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Sub Class Declarations
  intersection of: Restriction
    on property: numerator
    all values from: Object Property Class Assertion
metric definition: Formally, the relationship Diversity (RR) of a schema is defined as the ratio of the number of relationships (P) defined in the schema, divided by the sum of the number of subclasses (SC) (which is the same as the number of inheritance relationships). RR = P / (SC + P)
metric description: This metric reflects the diversity of relations and placement of relations in the ontology. An ontology that contains many relations other than class-subclass relations is richer than a taxonomy with only class-subclass relationships.
metric interpretation: The result of the formula will be a percentage representing how much of the connections between classes are rich relationships compared to all of the possible connections that can include rich relationships and inheritance relationships. For example, if an ontology has an RR close to zero, that would indicate that most of the relationships are class-subclass (i.e. ISA) relationships. In contrast, an ontology with a RR close to one would indicate that most of the relationships are other than class-subclass.

OntoQA Schema Deepness
type: Class
subclass of: OntoQA Schema Metrics
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Classes (Class Count)
  intersection of: Restriction
    on property: numerator
    all values from: Sub Class Declarations
metric definition: The schema depth of the schema (SD) is defined as the average number of subclasses per class. SD = H/C
metric description: This measure describes the distribution of classes across different levels of the ontology inheritance tree. This measure can distinguish a shallow ontology from a deep ontology. A shallow ontology is an ontology that has a small number of inheritance levels, and each class has a relatively large number of subclasses. In contrast, a deep ontology contains a large number of inheritance levels where classes have a small number of subclasses
metric interpretation: An ontology with a low SD would be deep, which indicates that the ontology covers a specific domain in a detailed manner (e.g. ProPreO [27]), while an ontology with a high SD would be a shallow (or horizontal) ontology (e.g. TAP), which indicates that the ontology represents a wide range of general knowledge with a low level of detail.

OntoQA Schema Metrics
type: Class
subclass of: OntoQA
metric description: The schema metrics address the design of the ontology schema. Although it is difficult to know if the ontology design correctly models the knowledge of the domain it is trying to represent, we provide some metrics that indicate different features of an ontology schema.

Path Length To Leaf Classes
type: Class
subclass of: Path Metrics
metric definition: The summed up length of the pathes from root to the leaf classes.

Path Metrics
type: Class
subclass of: Graph Metrics
metric description: Measurements that are concerned with the various paths in a graph (A path is the structure from the root class to the elements or leafes.)

Paths Overall
type: Class
subclass of: Path Metrics
subclass of: Restriction
  on property: implementedBy
  has value: pathsToLeafClasses
metric definition: Number of distinct paths from leaf classes to the root classes

Property Metrics
type: Class
subclass of: Elemental Metrics
metric description: Metrics that are concerned with properties than can be assigned to classes. That includes data-, annotation-, or object property metrics.

Quality Dimension
type: Class
comment: Quality Dimensions. Currently not part of NEOntometrics. Some frameworks propose metrics that are connected to quality measurements. These informations are captured in this class.

Quality Frameworks
type: Class
metric description: Data on the Ontology Frameworks. These frameworks utilize the metrics named in the "Elemental Metric" Section.

Reading Error
type: Class
subclass of: Repository Metrics
subclass of: Restriction
  on property: implementedBy
  has value: ReadingError
metric definition: The error message (if any).
metric interpretation: At times, the calculation does not function properly. In these cases, the error message is shown in this field.

Reasoner Active
type: Class
subclass of: Special Metrics
subclass of: Restriction
  on property: implementedBy
  has value: reasonerActive
metric definition: States whether the reasoner was active while calculating this ontology.

Reflexive Object Properties
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: reflexiveObjectPropertyAxioms
metric definition: Counts the number of object properties that are "reflexive".
metric description: If an object property is reflexive, then all object properties are connected to themselfes through this property.

Relation Assertion on Relation
type: Class
subclass of: Relation Metrics
metric definition: Counts how much a relation is used in instances.
metric description: individuals can be set in relation to each other using object properties. This metric counts how often a specific object property is used to connect individuals.

Relation Metrics
type: Class
subclass of: Iterative Metrics
metric description: These metrics are concerned with the individual object property relations. They are calculated per object property.

Relationship Assertions on Class
type: Class
subclass of: Class Metrics
metric definition: Counts the number of relationship assertions on a class.
metric description: Classes can be connected to other classes using object properties. This measurement counts how many classes are connected to a specific class using object properties in the subClassOf Signature.

Repository Metrics
type: Class
subclass of: Elemental Metrics
metric description: Attributes (mostly textual) that originate from the repository.

Same Individuals
type: Class
subclass of: Instances Metrics
subclass of: Restriction
  on property: implementedBy
  has value: sameIndividualsAxioms
metric definition: Counts the number of equal individual axioms.
metric description: Equal individuals are equivalent to each other. They can be used synonym to one another, all that is derived for one of the individuals will also be derived for the other.

SemoticSuite
type: Class
subclass of: Quality Dimension
see also: Burton-Jones, Andrew; Storey, Veda C.; Sugumaran, Vijayan; Ahluwalia, Punit (2005): A semiotic metrics suite for assessing the quality of ontologies. In Data & Knowledge Engineering 55 (1), pp. 84–102. DOI: 10.1016/j.datak.2004.11.010.

SemoticSuite Authority
type: Class
subclass of: SemoticSuite Social Quality
disjoint with: SemoticSuite History
metric definition: Let an ontology in the library be OA. Let the set of other ontologies in the library be L. Let the total number of links from ontologies in L to OA be K. Let the average value for K across ontology library be V. Then OT = K/V

SemoticSuite Clarity
type: Class
subclass of: SemoticSuite Semantic Quality
metric definition: Let Ci = name of class or property in ontology. "Ci, count Ai, (the number of word senses for that term in WordNet). Then EA = A/C

SemoticSuite Comprehensivness
type: Class
subclass of: SemoticSuite Pragmatic Quality
metric definition: Let C be the total number of classes and properties in ontology. Let V be the average value for C across entire library. Then PO = C/V

SemoticSuite Consistency
type: Class
subclass of: SemoticSuite Semantic Quality
metric definition: Let I= 0. Let C be the number of classes and properties in ontology. "Ci, if meaning in ontology is inconsistent, I+ 1. Therefore, I= number of terms with inconsistent meaning. EC = I/C

SemoticSuite History
type: Class
subclass of: SemoticSuite Social Quality
metric definition: Let the total number of accesses to an ontology be A. Let the average value for A across ontology library be H. Then OH = A/H

SemoticSuite Interpretability
type: Class
subclass of: SemoticSuite Semantic Quality
metric definition: Let C be the total number of terms used to define classes and properties in ontology. Let Wbe the number of terms that have a sense listed in WordNet. Then EI =W/C

SemoticSuite Lawfulness
type: Class
subclass of: SemoticSuite Syntactic Quality
disjoint with: SemoticSuite Richness
metric definition: Let X be total syntactical rules. Let Xb be total breached rules. Let NS be the number of statements in the ontology. Then SL = Xb/NS

SemoticSuite Relevance
type: Class
subclass of: SemoticSuite Pragmatic Quality
metric definition: Let NS be the number of statements in the ontology. Let S be the type of syntax relevant to agent. Let R be the number of statements within NS that use S.PR = R/NS

SemoticSuite Richness
type: Class
subclass of: SemoticSuite Syntactic Quality
metric definition: Let Y be the total syntactical features available in ontology language. Let Z be the total syntactical features used in this ontology. Then SR = Z/Y

Size
type: Class
subclass of: Repository Metrics
subclass of: Restriction
  on property: implementedBy
  has value: Size
type: NamedIndividual
metric definition: The size of a commit (in bytes)
metric description: Highly dependent on the formalization. E.g., Turtle (.ttl) is more space-efficient than xml.

Special Metrics
type: Class
subclass of: Elemental Metrics
metric description: This category collects metrics that cannot be accounted to the other categories.

Sub Class Declarations
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: subClassOfAxioms
metric definition: The number of rdfs:SubClassOf Declarations
metric description: Sub classes allow the construction of more detailed, complex hierachies.
metric interpretation: A high number of subclass statements indicate a rich ontology taxonomy.

Sub Object Properties
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: subObjectPropertyOfAxioms
metric definition: Counts the number of subObjectProperty axioms.
metric description: Properties can be aligned in hierachical order. All individuals that are part of the bottom entity are then also part of the top entity (E.g., isFather subPropertyOf isParent).

Sub Property Chain Of Count
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: subPropertyChainOfAxioms
metric definition: The number of chained sub object properties
metric description: A specialized cyclic relationship that does not lead to decidability problems. E.g.: "The sibling of someones child is his child".

Subclasses of Thing
type: Class
subclass of: Conditioned Metrics
subclass of: Restriction
  on property: implementedBy
  has value: rootClasses
metric definition: Counts all classes that do not have parent classes. Note, that the classes do not necessarily need the statement "rdfs:subClassOf owl:Thing" to be counted.
metric description: All the classes at the top of an ontology. It tells us how many "entrypoints" in the inheritance tree exist .

Super Classes
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: superClasses
metric definition: Sum of the number of Parents of classes
metric description: A super class is the direct parent of a class. Through multiple inheritance, one class can have more than one superclass.

Super Classes of Leaf Classes
type: Class
subclass of: Conditioned Metrics
subclass of: Restriction
  on property: implementedBy
  has value: superClassesOfLeafClasses
metric definition: Counts the number of parents of the leaf classes
metric interpretation: Allows to interpret how the level above the last level is structured. E.g., are there much more "super classes of leaf classes" than "leaf classes"? Then the leafes have a high multi inheritance ratio.

Superclasses of Classes with Multiple Inheritance
type: Class
subclass of: Conditioned Metrics
subclass of: Restriction
  on property: implementedBy
  has value: superClassesOfClassesWithMultipleInheritance
metric definition: Counts how many parents the classes with multiple inheritance have
metric interpretation: In combination with the number of classes with mutlple inheritance, it shows how far spread out the multi iinheritance relationships are. E.g., Do they, on average, have just one 2,1 classes? Then most of the multiple inheritance classes have just two parents.

Symmetric Object Properties
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: symmetricObjectPropertyAxioms
metric definition: Counts the number of object properties that are "symmetric".
metric description: If an object property is symmetric, and a relation of individual A->B exist, then there is the same relation B-A. E.g., A isFriendOf B, then B isFriendOf A

Total Breath
type: Class
subclass of: Breath Metrics
subclass of: Restriction
  on property: implementedBy
  has value: absoluteBreadth
metric definition: The number of all siblings.
metric description: Counts all siblings on all depth levels of the ontology.

Total Depth
type: Class
subclass of: Depth Metrics
subclass of: Restriction
  on property: implementedBy
  has value: absoluteDepth
metric definition: The depth of all paths accumulated
metric description: The summed up depth of all paths in an ontology. E.g., path a from ROOT to leaf class A has 3 levels, path b has 2, etc.

Transitive Object Properties
type: Class
subclass of: Object Property Characteristics
subclass of: Restriction
  on property: implementedBy
  has value: transitiveObjectPropertyAxioms
metric definition: Counts the number of object properties that are "transitive".
metric description: If an object property is transitive, and the individuals are connected as A->B->C, then follows A->C. E.g., If Peter is an ancestorOf Paul, and Paul is an ancestorOf Brian, then Peter is also an ancestorOf Brian.

max Fanoutness of Leaf Classes
type: Class
subclass of: Leaf Metrics
subclass of: Restriction
  on property: implementedBy
  has value: maxFanoutnessOfLeafClasses
metric description: Calculates the maximum number of siblings of the leaf classes.
metric description: This metric measures the maximum amount of leafclasses on a parent class.

pk
type: Class
subclass of: Repository Metrics
subclass of: Restriction
  on property: implementedBy
  has value: pk
type: NamedIndividual
metric interpretation: Required for internal purposes.
metric definition: NEOntometrics internal information. The primary key that identifies a repository in the database.

recursive Sub Classes
type: Class
subclass of: Basic Metrics
subclass of: Restriction
  on property: implementedBy
  has value: recursiveSubClasses
metric definition: Counts the number of subclasses per class iteratively. Also refered to as fan-outness per some papers, though the definition is differently for the papers.
metric description: If b subClassOf a, c subClassOf a and b subClassOf b, then the metric would calculate to a 4, as it first recursivly checks all subClasses of a, then of b, and so on.

Complexity Cohesion Average Fanout of Non-Leaf Classes (AF-NL)
type: Class
subclass of: Complexity Cohesion
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: recursive Sub Classes
  intersection of: Restriction
    on property: numerator
    all values from: Classes With Subclasses
metric definition: The Average Fanout of Non-LeafClasses (AF-NL) is defined as the Number of Fanouts (NoF) divided by Number of Non-leaf Classes explicitly defined in the ontology Oi .

Complexity Cohesion Average Fanout of Root Class (AF-R)
type: Class
subclass of: Complexity Cohesion
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: recursive Sub Classes
  intersection of: Restriction
    on property: numerator
    all values from: Subclasses of Thing
metric definition: The Average Fanout of Root Classes (AF-R) is defined to be the Number of Fanouts (NoF) divided by the Number of Root Classes in the ontology Oi .

Complexity Cohesion Average Fanout per Class (AF-C)
type: Class
subclass of: Complexity Cohesion
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: recursive Sub Classes
  intersection of: Restriction
    on property: numerator
    all values from: Classes (Class Count)
metric definition: The Average Fanout per Class (AF-C) is the Number of Fanouts (NoF) divided by Number of Classes (NoC) explicitly defined in the ontology Oi

Complexity Cohesion Average Properties per Class (AP-C)
type: Class
subclass of: Complexity Cohesion
subclass of: Class
  intersection of: Restriction
    on property: divisor
    all values from: Object Property Class Assertion
  intersection of: Restriction
    on property: numerator
    all values from: Classes (Class Count)
metric definition: The Average Properties per Class (AP-C) is the number of properties explicitly defined in the ontology Oi divided by the number of classes explicitly defined in the ontology Oi .

Complexity Cohesion Maximum Depth of Inheritance Tree (MaxDIT)
type: Class
subclass of: Complexity Cohesion
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Maximum Depth
metric definition: The Maximum Depth of Inheritance Tree (MaxDIT) of the ontology Oi is defined as follows. A depth is the total number of nodes in a path. A path starts from the root node to the leaf node. All distinct paths in the ontology Oi include every path from each root node to each leaf node if there exists an inheritance path from the root node to the leaf node. The root node is the first level in each path.

Complexity Cohesion Number of Properties (NOP)
type: Class
subclass of: Complexity Cohesion
subclass of: Restriction
  on property: directlyUsesMetric
  all values from: Object Property Class Assertion
metric definition: Number of Properties (NoP) is the number of properties explicitly defined in the ontology Oi .
metric description: Example. Each class can possess properties (but is not required to). Class 1 has one property, class 2 has two properties, class 3 has no properties, class 4 has three properties, and class 5 has one property. Thus, NoP = 7.

OQuaRE Knowledge Acquisition – Representation
type: Class
subclass of: OQuaRE Functional Adequacy
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Annotation Richness
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Number of properties
subclass of: Restriction
  on property: positiveAffectedBy
  some values from: Relationship Richness
metric definition: Capability of the Ontology to represent the knowledge acquired.
metric description: Knowledge acquisition is the gathering, storage, and encoding of existing information.