Machine Learning Schema
type: Ontology
version IRI: mls#
description: ML-Schema is a collaborative, community effort with a mission to develop, maintain, and promote standard schemas for data mining and machine learning algorithms, datasets, and experiments
has version: 1.0
license: https://creativecommons.org/licenses/by/4.0/

achieves
type: ObjectProperty
domain: Run
range: Task
description: A relation between a run and a task, where the run achieves specifications formulated by the task.

definedOn
type: ObjectProperty
sub property of: topObjectProperty
inverse of: defines
domain: Task
range: Class
  union of: Data
  union of: EvaluationSpecification
description: A relation between a task and either the data or an evaluation specification pertinent to this task.

executes
type: ObjectProperty
sub property of: topObjectProperty
domain: Run
range: Implementation
description: A relation between a run and an implemantation that is being executed during the run.

hasHyperParameter
type: ObjectProperty
sub property of: topObjectProperty
domain: Implementation
range: HyperParameter
description: A relation between an implementation of a machine learning algorithm and its hyperparameter.

hasInput
type: ObjectProperty
sub property of: topObjectProperty
domain: Run
range: Class
  union of: Data
  union of: HyperParameterSetting
description: A relation between a run and data that is taken as input to the run.

hasOutput
type: ObjectProperty
domain: Run
range: Class
  union of: Model
  union of: ModelEvaluation
description: A relation between a run and either a model or model evaluation that is produced on it’s output.

hasPart
type: ObjectProperty
description: A relation which represents a part-whole relationship holding between an entity and its part.

hasQuality
type: ObjectProperty
description: A relation between entities and their various characteristics.

implements
type: ObjectProperty
domain: InformationEntity
range: InformationEntity
description: A relation between an information entity and a specification that it conforms to.

realizes
type: ObjectProperty
sub property of: topObjectProperty
domain: Run
range: Algorithm
description: A relation between a run and an algorithm, where the run realizes specifications formulated by the algorithm.

specifiedBy
type: ObjectProperty
range: InformationEntity
description: A relation between an entity and the information content entity that specifies it.

Algorithm
type: Class
subclass of: InformationEntity
description: The algorithm regardless software implementation.

Data
type: Class
subclass of: InformationEntity
subclass of: Restriction
  on property: hasQuality
  some values from: DataCharacteristic
description: Data is a data item composed of data examples and it may be of a various level of granularity and complexity. With regard to granularity, it can be a whole dataset (for instance, one main table and possibly other tables), or only a single table, or only a feature (e.g., a column of a table), or only an instance (e.g., row of a table), or a single feature-value pair. With regard to complexity, data examples are characterized by their datatype, which may be arbitrarily complex (e.g., instead of a table it can be an arbitrary graph).

DataCharacteristic
type: Class
subclass of: Quality
description: DataCharacteristic is a distinguishing quality or property that distinguish one data from another. Such characteristics are often statistical ones (e.g., the number of instances or the number of features of a data set). They may be also informationtheoretic measures (e.g., class entropy of a categorical data set) or geometric measures of data complexity (e.g., the highest discriminatory power of any single feature in the data set).

EvaluationMeasure
type: Class
subclass of: InformationEntity
description: EvaluationMeasure is a measure to assess the performance of the model generated by the process that realizes the task. Examples are predictive accuracy or f-measure.

EvaluationProcedure
type: Class
subclass of: InformationEntity
description: EvaluationProcedure is a technique to evaluate machine learning models. Examples are cross-validation and leave-one-out.

EvaluationSpecification
type: Class
subclass of: InformationEntity
subclass of: Restriction
  on property: defines
  some values from: Task
subclass of: Restriction
  on property: hasPart
  some values from: EvaluationMeasure
subclass of: Restriction
  on property: hasPart
  some values from: EvaluationProcedure
description: EvaluationSpecification is a specification of an evaluation measure and an evaluation procedure to assess the performance of the process that realizes the task.
comment: EvaluationProcedure is a technique to evaluate machine learning models. Examples are cross-validation and leave-one-out.

Experiment
type: Class
subclass of: Process
subclass of: Restriction
  on property: hasPart
  some values from: Run
description: Experiment is a collection of runs.

HyperParameter
type: Class
subclass of: InformationEntity
description: Hyperparameter is a prior parameter of an implementation, i.e., a parameter which is set before its execution (e.g. C, the complexity parameter, in weka.SMO).

HyperParameterSetting
type: Class
subclass of: InformationEntity
subclass of: Restriction
  on property: specifiedBy
  some values from: HyperParameter
subclass of: Restriction
  on property: hasValue
  some values from: Literal
description: HyperParameterSetting is an entity which connects a hyperparameter and its value that is being set before an implementation execution.

Implementation
type: Class
subclass of: InformationEntity
subclass of: Restriction
  on property: hasHyperParameter
  some values from: HyperParameter
subclass of: Restriction
  on property: hasQuality
  some values from: ImplementationCharacteristic
subclass of: Restriction
  on property: implements
  some values from: Algorithm
description: Implementation is an executable implementation of a machine learning algorithm, a script, or a workflow. It is versioned, and sometimes belongs to a library (e.g. WEKA).

ImplementationCharacteristic
type: Class
subclass of: Quality
description: ImplementationCharacteristic is a distinguishing quality or property that distinguish one implementation from another.

Model
type: Class
subclass of: InformationEntity
subclass of: Restriction
  on property: hasQuality
  some values from: ModelCharacteristic
description: Model is a generalization of a set of training data able to predict values for unseen instances. It is an output from an execution of a data mining algorithm implementation. Models have a dual nature. They can be treated as data structures and as such represented, stored and manipulated. On the other hand, they act as functions and are executed, taking as input data examples and giving as output the result of applying the function to a data example. Models can also be divided into global or local ones. A global model has global coverage of a data set, i.e., it generalizes the whole data set. A local model, such as a pattern set, is a set of local hypotheses, i.e. each applies to a limited region of the data set.

ModelCharacteristic
type: Class
subclass of: Quality
description: ModelCharacteristic is a distinguishing quality or property that distinguish one model from another. An example model characetristic may be interpretabilty or a complexity of the model.

ModelEvaluation
type: Class
subclass of: InformationEntity
subclass of: Restriction
  on property: specifiedBy
  some values from: EvaluationMeasure
subclass of: Restriction
  on property: hasValue
  some values from: Literal
description: ModelEvaluation is a setting of a value of the performance measure specified by the evaluation specification. It connects a measure specification with its value.

Process
type: Class
disjoint with: Quality

Run
type: Class
subclass of: Process
subclass of: Restriction
  on property: achieves
  some values from: Task
subclass of: Restriction
  on property: executes
  some values from: Implementation
subclass of: Restriction
  on property: hasInput
  some values from: Data
subclass of: Restriction
  on property: hasInput
  some values from: HyperParameterSetting
subclass of: Restriction
  on property: hasOutput
  some values from: Model
subclass of: Restriction
  on property: hasOutput
  some values from: ModelEvaluation
subclass of: Restriction
  on property: realizes
  some values from: Algorithm
description: Run is an execution of an implementation on a machine (computer). It is limited in time (has a start and end point), can be successful or failed.

Software
type: Class
subclass of: InformationEntity
subclass of: Restriction
  on property: hasPart
  some values from: Implementation
description: Software is implemented computer programs, procedures, scripts or rules with associated documentation, possibly constituting an organized environment, stored in read/write memory for the purpose of being executed within a computer system.

Study
type: Class
subclass of: Process
subclass of: Restriction
  on property: hasPart
  some values from: Experiment
description: Study is a collection of runs that belong together to do some kind of analysis on its results. This analysis can be general or very specific (e.g. a hypothesis test). Can be linked to files, data, that belong to it.

Task
type: Class
subclass of: InformationEntity
subclass of: Restriction
  on property: definedOn
  some values from: Data
description: Task is a formal description of a process that needs to be completed (e.g. based on inputs and outputs). A Task is any piece of work that needs to be addressed in the data mining process. In ML Schema, it is defined based on data.

Dublin Core Metadata Element Set, Version 1.1
publisher: DCMI
modified: 2012-06-14

Contributor
has version: contributor-006
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
comment: An entity responsible for making contributions to the resource.
description: Examples of a Contributor include a person, an organization, or a service. Typically, the name of a Contributor should be used to indicate the entity.
modified: 2008-01-14
issued: 1999-07-02

Coverage
has version: coverage-006
modified: 2008-01-14
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
comment: The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant.
description: Spatial topic and spatial applicability may be a named place or a location specified by its geographic coordinates. Temporal topic may be a named period, date, or date range. A jurisdiction may be a named administrative entity or a geographic place to which the resource applies. Recommended best practice is to use a controlled vocabulary such as the Thesaurus of Geographic Names [TGN]. Where appropriate, named places or time periods can be used in preference to numeric identifiers such as sets of coordinates or date ranges.
issued: 1999-07-02

Creator
modified: 2008-01-14
comment: An entity primarily responsible for making the resource.
description: Examples of a Creator include a person, an organization, or a service. Typically, the name of a Creator should be used to indicate the entity.
has version: creator-006
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
issued: 1999-07-02

Date
issued: 1999-07-02
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
modified: 2008-01-14
comment: A point or period of time associated with an event in the lifecycle of the resource.
has version: date-006
description: Date may be used to express temporal information at any level of granularity. Recommended best practice is to use an encoding scheme, such as the W3CDTF profile of ISO 8601 [W3CDTF].

Description
description: Description may include but is not limited to: an abstract, a table of contents, a graphical representation, or a free-text account of the resource.
issued: 1999-07-02
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
comment: An account of the resource.
modified: 2008-01-14
has version: description-006

Format
issued: 1999-07-02
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
modified: 2008-01-14
comment: The file format, physical medium, or dimensions of the resource.
has version: format-007
description: Examples of dimensions include size and duration. Recommended best practice is to use a controlled vocabulary such as the list of Internet Media Types [MIME].

Identifier
has version: identifier-006
description: Recommended best practice is to identify the resource by means of a string conforming to a formal identification system.
comment: An unambiguous reference to the resource within a given context.
issued: 1999-07-02
modified: 2008-01-14
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.

Language
modified: 2008-01-14
issued: 1999-07-02
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
has version: language-007
description: Recommended best practice is to use a controlled vocabulary such as RFC 4646 [RFC4646].
comment: A language of the resource.

Publisher
has version: publisher-006
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
issued: 1999-07-02
modified: 2008-01-14
description: Examples of a Publisher include a person, an organization, or a service. Typically, the name of a Publisher should be used to indicate the entity.
comment: An entity responsible for making the resource available.

Relation
has version: relation-006
description: Recommended best practice is to identify the related resource by means of a string conforming to a formal identification system.
modified: 2008-01-14
issued: 1999-07-02
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
comment: A related resource.

Rights
has version: rights-006
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
description: Typically, rights information includes a statement about various property rights associated with the resource, including intellectual property rights.
issued: 1999-07-02
modified: 2008-01-14
comment: Information about rights held in and over the resource.

Source
has version: source-006
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
comment: A related resource from which the described resource is derived.
modified: 2008-01-14
description: The described resource may be derived from the related resource in whole or in part. Recommended best practice is to identify the related resource by means of a string conforming to a formal identification system.
issued: 1999-07-02

Subject
description: Typically, the subject will be represented using keywords, key phrases, or classification codes. Recommended best practice is to use a controlled vocabulary.
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
issued: 1999-07-02
comment: The topic of the resource.
modified: 2012-06-14
has version: subject-007

Title
comment: A name given to the resource.
modified: 2008-01-14
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.
issued: 1999-07-02
has version: title-006

Type
comment: The nature or genre of the resource.
has version: type-006
description: Recommended best practice is to use a controlled vocabulary such as the DCMI Type Vocabulary [DCMITYPE]. To describe the file format, physical medium, or dimensions of the resource, use the Format element.
issued: 1999-07-02
modified: 2008-01-14
note: A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document "DCMI Metadata Terms" (http://dublincore.org/documents/dcmi-terms/) for an explanation.