# Data Quality Enhancement Controlled Vocabulary List of Terms **Title**
Data Quality Enhancement Controlled Vocabulary List of Terms **Date version issued**
2026-06-03 **Date created**
2025-05-10 **Part of TDWG Standard**
**Preferred namespace abbreviation**
bdqenh **This version**
**Latest version**
**Previous version**
**Abstract**
This document is a reference for the BDQ standard. It covers the vocabulary terms that are types of bdqffdq:Enhancement (originally defined in Veiga 2016 and Veiga et al. 2017) and form the controlled vocabulary for bdqffdq:hasEnhancement. **Authors**
[Lee Belbin](https://orcid.org/0000-0001-8900-6203) ([Blatant Fabrications](https://www.wikidata.org/wiki/Q130304884)), [Arthur D. Chapman](https://orcid.org/0000-0003-1700-6962) ([Australian Biodiversity Information Services](http://www.wikidata.org/entity/Q100600913)), [Paul J. Morris](https://orcid.org/0000-0002-3673-444X) ([Museum of Comparative Zoology, Harvard University](http://www.wikidata.org/entity/Q1420782)), [John Wieczorek](https://orcid.org/0000-0003-1144-0290) (Rauthiflor LLC) **Creator**
TDWG Biodiversity Data Quality Interest Group Task Group 2: Data Quality Tests and Assertions **Bibliographic citation**
TDWG Biodiversity Data Quality Interest Group Task Group 2: Data Quality Tests and Assertions. 2026. Data Quality Enhancement Controlled Vocabulary List of Terms. Biodiversity Information Standards (TDWG). **Status**
Draft Standard for Review ## Table of Contents ## - [1 Introduction (non-normative)](#1-introduction-non-normative) - [1.1 Purpose (non-normative)](#11-purpose-non-normative) - [1.2 Audience (non-normative)](#12-audience-non-normative) - [1.3 Data Quality Enhancements (non-normative)](#13-data-quality-enhancements-non-normative) - [1.4 Associated Documents (non-normative)](#14-associated-documents-non-normative) - [1.5 Term List Distributions (non-normative)](#15-term-list-distributions-non-normative) - [1.6 Status of the Content of this Document (normative)](#16-status-of-the-content-of-this-document-normative) - [1.7 RFC 2119 key words (normative)](#17-rfc-2119-key-words-normative) - [1.8 Namespace abbreviations (non-normative)](#18-namespace-abbreviations-non-normative) - [1.9 Key to Vocabulary Terms (normative)](#19-key-to-vocabulary-terms-normative) - [2 Use of Terms (normative)](#2-use-of-terms-normative) - [3 Term index (non-normative)](#3-term-index-non-normative) - [3.1 Index By Term Name (non-normative)](#31-index-by-term-name-non-normative) - [3.2 Index By Label (non-normative)](#32-index-by-label-non-normative) - [4 Vocabulary (normative)](#4-vocabulary-normative) - [Glossary (non-normative)](#glossary-non-normative) - [References (non-normative)](#references-non-normative) - [Cite BDQ (non-normative)](#cite-bdq-non-normative) ## 1 Introduction (non-normative) ### 1.1 Purpose (non-normative) The purpose of this document is to provide the full term list for the `bdqenh:` controlled vocabulary, which defines the values of `bdqffdq:Enhancement` used in BDQ `Amendment` Tests. Each `Enhancement` describes a general strategy by which data may be modified or supplemented to improve its quality in alignment with a specified `Use Case`. These terms support the formal description of how `Amendments` propose changes to data and clarify the intended nature of those proposals. ### 1.2 Audience (non-normative) This document is intended for users who need a technical understanding of how BDQ `Amendment` Tests describe proposed `Improvements` to data. It will be especially useful for: - Implementers developing systems that generate or evaluate data quality `Amendments` - Standards developers and data quality modelers working with the Fitness For Use Framework Ontology - Analysts and data curators reviewing Test results in the context of proposed changes to datasets Some familiarity with the structure of BDQ Tests and the Fitness For Use Framework Ontology is recommended. ### 1.3 Data Quality Enhancements (non-normative) The concept of `bdqffdq:Enhancement`, as defined by Veiga (2016) and Veiga et al. (2017), captures the general nature of a proposed change intended to improve data quality. Examples of `Enhancements` include `AssumedDefault`, `Converted`, `From`, `Standardized`, and `Transposed`. These represent high-level categories of `Amendment` strategies. `Enhancements` describe, in abstract terms, what a `bdqffdq:Specification` expresses concretely. While `Enhancements` are informally related to `Data Quality Dimensions` (e.g., a standardized `Enhancement` might relate to `Conformance`), those relationships are not formally encoded. Each `bdqffdq:Amendment` Test in `bdqtest:` proposes a change to one or more data values (`bdqffdq:InformationElements`) based on a specific `Enhancement`. For example, the Test [AMENDMENT_EVENTDATE_STANDARDIZED](../../terms/bdqtest/index.md#AMENDMENT_EVENTDATE_STANDARDIZED) evaluates the term `dwc:eventDate` and may propose a revised value formatted according to the ISO 8601 standard. The `Enhancement` in this case is `bdqenh:Standardized`. `Enhancements` are only applicable to Tests of type `bdqffdq:Amendment`. ### 1.4 Associated Documents (non-normative) For the list and links to all associated documents see [The Biodiversity Data Quality (BDQ) Standard](../../../index.md). ### 1.5 Term List Distributions (non-normative) | Description | IRI | Download URL | Notes | | ----------- | --- | ----------- | ----- | | HTML file | https://rs.tdwg.org/bdqenh/terms/ | https://raw.githubusercontent.com/tdwg/bdq/master/tg2/_review/docs/list/bdqenh/index.md | This file | | RDF/XML file | TBD | https://raw.githubusercontent.com/tdwg/bdq/master/tg2/_review/dist/bdqenh.xml | Example for submission, to be generated | ### 1.6 Status of the Content of this Document (normative) Sections may be either normative (defines what is required to comply with the standard) or non-normative (supports understanding but is not binding) and are marked as such. Any sentence or phrase beginning with "For example" or "e.g.", whether in a normative section or a non-normative section, is non-normative. Section [1.9 Key to Vocabulary Terms (normative)](#19-key-to-vocabulary-terms-normative) identifies which values in Section 4 are normative and which are non-normative. ### 1.7 RFC 2119 key words (normative) The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC 2119](https://tools.ietf.org/html/rfc2119). ### 1.8 Namespace abbreviations (non-normative) The following namespace abbreviations are used in this document: | **Abbreviation** | **Namespace** | | ------------ | ------------- | | bdqdim: | https://rs.tdwg.org/bdqdim/terms/ | | **bdqenh:** | https://rs.tdwg.org/bdqenh/terms/ | | bdqffdq: | https://rs.tdwg.org/bdqffdq/terms/ | | bdqtest: | https://rs.tdwg.org/bdqtest/terms/ | | dcterms: | http://purl.org/dc/terms/ | | dwc: | http://rs.tdwg.org/dwc/terms/ | | rdf: | http://www.w3.org/1999/02/22-rdf-syntax-ns# | | rdfs: | http://www.w3.org/2000/01/rdf-schema# | | skos: | http://www.w3.org/2004/02/skos/core# | | tdwgutility: | http://rs.tdwg.org/dwc/terms/attributes/ | ### 1.9 Key to Vocabulary Terms (normative) The terminology used to describe the terms in this vocabulary follows the TDWG [TDWG Standards Documentation Standard (SDS)](https://www.tdwg.org/standards/sds/). Each term definition includes the original RDF definition, and may also provide a TDWG-specific interpretation from the SDS, as well as a definition tailored to this local context. | Label (Term) | Normative | Definition | Example | | ------------ | --------- | ---------- | ------- | | Term Name (rdf:value) | normative | Idiomatic property used for structured values. TDWG SDS: The term name is a controlled value that represents the class, property, or concept described by the term definition. | AssumedDefault | | Term IRI (dcterms:isVersionOf) | normative | A related resource of which the described resource is a version, edition, or adaptation. TDWG SDS: The HTTP IRI that uniquely identifies the current term. | [https://rs.tdwg.org/ bdqenh/terms/ AssumedDefault](https://rs.tdwg.org/bdqenh/terms/AssumedDefault) | | Modified (dcterms:issued) | normative | Date of formal issuance of the resource. TDWG SDS: The date in ISO 8601 Date format on which the most recent version of the term was issued. | 2024-09-30 | | Term Version IRI (rdf:about) | normative | The HTTP IRI that identifies the version of the term that is currently in force. | [https://rs.tdwg.org/ bdqenh/terms/ AssumedDefault-2024-09-30](https://rs.tdwg.org/bdqenh/terms/AssumedDefault-2024-09-30) | | Label (rdfs:label) | normative | A human-readable name for the subject. TDWG SDS: A a word or short phrase that serves as a human-readable name for the term. | Assumed Default | | Definition (rdfs:comment) | normative | A description of the subject resource. TDWG SDS: The normative definition of the term, written in English. | Data could be improved by setting an empty value to a default value. | | Comments (skos:note) | non-normative | A general note, for any purpose. | Data in a bdqffdq:InformationElement are absent and may be proposed to be filled in with a default value. Corresponding dimension is bdqdim:Completeness. | | Status (tdwgutility:status) | | Used to indicate if the term is recommended for use or if it is only of historical significance. | recommended | | Controlled Value () | normative | A string that is unique within a controlled vocabulary that identifies the concept in the context of a text-based metadata transfer system. The value MUST consist of Unicode characters. | AssumedDefault | | Type (rdf:type) | normative | The subject is an instance of a class. | bdqffdq:Enhancement | ## 2 Use of Terms (normative) In an RDF context, a reference to a term in the `bdqenh:` namespace MUST use the Term IRI (e.g., `https://rs.tdwg.org/bdqenh/terms/AssumedDefault`) or Term Qualified name (e.g., `bdqenh:AssumedDefault`). In a non-RDF context in which resources may be used by software (e.g., a value in a spreadsheet or database table) the Controlled Value String (local name, e.g., `AssumedDefault`) SHOULD be used. In a purely human context a label (e.g., `Assumed Default`) MAY be used. Each instance of `bdqffdq:Amendment` SHOULD have exactly one `bdqffdq:hasEnhancement` property relating it to a term in this `bdqenh:` vocabulary. An instance of `bdqffdq:Validation`, `bdqffdq:Issue`, or `bdqffdq:Measure` SHOULD NOT have a `bdqffdq:hasEnhancement` property relating it to a term in this `bdqenh:` vocabulary. ## 3 Term index (non-normative) ### 3.1 Index By Term Name (non-normative) (See also [3.2 Index By Label (non-normative)](#32-index-by-label-non-normative)) **Vocabulary** [bdqenh:AssumedDefault](#bdqenh_AssumedDefault) | [bdqenh:Converted](#bdqenh_Converted) | [bdqenh:FilledInFrom](#bdqenh_FilledInFrom) | [bdqenh:Standardized](#bdqenh_Standardized) | [bdqenh:Transposed](#bdqenh_Transposed) ### 3.2 Index By Label (non-normative) (See also [3.1 Index By Term Name (non-normative)](#31-index-by-term-name-non-normative)) [Assumed Default](#bdqenh_AssumedDefault) | [Converted](#bdqenh_Converted) | [Fill In From](#bdqenh_FilledInFrom) | [Standardized](#bdqenh_Standardized) | [Transposed](#bdqenh_Transposed) ## 4 Vocabulary (normative)

Term Name bdqenh:AssumedDefault
Term IRI	https://rs.tdwg.org/bdqenh/terms/AssumedDefault
Modified	2024-09-30
Term version IRI	https://rs.tdwg.org/bdqenh/terms/AssumedDefault-2024-09-30
Label	Assumed Default
Definition	Data could be improved by setting an empty value to a default value.
Comments	Data in a bdqffdq:InformationElement are absent and may be proposed to be filled in with a default value. Corresponding dimension is bdqdim:Completeness.
Status	recommended
Controlled value	AssumedDefault
Type	bdqffdq:Enhancement

Term Name bdqenh:Converted
Term IRI	https://rs.tdwg.org/bdqenh/terms/Converted
Modified	2024-09-30
Term version IRI	https://rs.tdwg.org/bdqenh/terms/Converted-2024-09-30
Label	Converted
Definition	Data could be improved by converting from one representation to another.
Comments	As in spatial coordinate transformations. Data in a bdqffdq:InformationElement that do not conform to some specification may be proposed to be replaced with a conforming value. Corresponding dimension is bdqdim:Conformance.
Status	recommended
Controlled value	Converted
Type	bdqffdq:Enhancement

Term Name bdqenh:FilledInFrom
Term IRI	https://rs.tdwg.org/bdqenh/terms/FilledInFrom
Modified	2024-09-30
Term version IRI	https://rs.tdwg.org/bdqenh/terms/FilledInFrom-2024-09-30
Label	Fill In From
Definition	Data could be improved by using one data value to fill in the empty value in another.
Comments	As in filling in from verbatim terms. Data in a bdqffdq:InformationElement are absent and may be proposed to be filled in by interpretation of values in one or more other terms. Corresponding dimension is bdqdim:Completeness.
Status	recommended
Controlled value	FilledInFrom
Type	bdqffdq:Enhancement

Term Name bdqenh:Standardized
Term IRI	https://rs.tdwg.org/bdqenh/terms/Standardized
Modified	2024-09-30
Term version IRI	https://rs.tdwg.org/bdqenh/terms/Standardized-2024-09-30
Label	Standardized
Definition	Data could be improved by conforming them to a standard representation.
Comments	Data in a bdqffdq:InformationElement that do not conform to some format, syntax, data type, or standard may be proposed to be replaced with a conforming value. Corresponding dimension is bdqdim:Conformance.
Status	recommended
Controlled value	Standardized
Type	bdqffdq:Enhancement

Term Name bdqenh:Transposed
Term IRI	https://rs.tdwg.org/bdqenh/terms/Transposed
Modified	2024-09-30
Term version IRI	https://rs.tdwg.org/bdqenh/terms/Transposed-2024-09-30
Label	Transposed
Definition	Data could be improved by switching values between two or more fields.
Comments	Data in a set of at least two bdqffdq:InformationElements that do not conform to expectations may be proposed to have their values switched in order to produce conforming values. Corresponding dimension is bdqdim:Consistency.
Status	recommended
Controlled value	Transposed
Type	bdqffdq:Enhancement

## Glossary (non-normative) A glossary of acronyms and terms additional to those in the various namespaces can be found in the [Glossary (non-normative)](../../../index.md#6-glossary-non-normative) section of the Biodiversity Data Quality (BDQ) landing page. ## References (non-normative) The references for the BDQ standard can be found in the [References (non-normative)](../../../index.md#7-references-non-normative) section of the Biodiversity Data Quality (BDQ) landing page. ## Cite BDQ (non-normative) **To cite BDQ in general, use the peer-reviewed article:** Chapman AD, Belbin L, Zermoglio PF, Wieczorek J, Morris PJ, Nicholls M, Rees ER, Veiga AK, Thompson A, Saraiva AM, James SA, Gendreau C, Benson A, Schigel D (2020). Developing Standards for Improved Data Quality and for Selecting Fit for Use Biodiversity Data. Biodiversity Information Science and Standards 4: e50889. https://doi.org/10.3897/biss.4.50889 **To cite this document specifically, use the following:** TDWG Biodiversity Data Quality Interest Group Task Group 2: Data Quality Tests and Assertions. 2026. Data Quality Enhancement Controlled Vocabulary List of Terms. Biodiversity Information Standards (TDWG). **Biodiversity Information Standards (TDWG)** This content made open by Biodiversity Information Standards (TDWG) is licensed under a [Licensed under a Creative Commons Attribution 4.0 International (CC BY) License.](http://creativecommons.org/licenses/by/4.0/)