Vocabulary Documentation
Introduction
This document provides practical guidance on the use of vocabularies in LINCS datasets: how to identify suitable vocabularies, how to choose which ones to adopt, and how to apply their terms. It also provides information about current vocabulary usage across the project.
The requirements LINCS places on vocabularies and the responsibilities for their development and maintenance are established in the related Vocabulary Policy.
Two further pages complete the documentation: LINCS-hosted Vocabularies describes the vocabularies LINCS hosts and the process for contributing terms to them, while the SKOS Vocabulary Guidelines sets out the technical requirements for creating one.
Vocabularies and Authority Files
First of all, it is important to clarify the distinction between vocabularies and authority files. A vocabulary is a set of terms that are used as types of entities. On the other hand, an authority file provides identifiers and descriptions of the actual entities, such as people, places, things, or concepts.
| Resource | Definition | Example use |
|---|---|---|
| Controlled vocabulary | “A standardized and organized arrangement of words and phrases, which is used to consistently describe data.” | Typing an object as a painting using the Getty AAT. |
| Authority file | “A list that contains the authoritative way to reference people, places, things, or concepts.” | Identifying the specific person Virginia Woolf using VIAF. |
What Counts as a Vocabulary
LINCS adopts an operational definition of vocabulary based on term usage rather than on a specific set of structural requirements or implementation technologies. A vocabulary term <X> is any Uniform Resource Identifier (URI) that belongs to at least one of the following triple statements in the LINCS triplestore:
<X> rdf:type crm:E55_Type→ The term is explicitly declared as a type in CIDOC CRM.<X> rdf:type skos:Concept→ The term is explicitly declared as a SKOS concept.<Y> crm:P2_has_type <X>→ The term is used as a type for another entity.
A term does not need to satisfy all three conditions at the same time. Any one of them is sufficient. In practice this means that any entity declared to be a type, or directly used as a type for another entity, is a vocabulary term, and the source of that term qualifies as a vocabulary for the purposes of LINCS. The diagram below shows the three conditions.
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For more information, see also the Definition of Vocabulary in LINCS and examples found in the Vocabulary Policy.
What Counts as an Authority File
While a vocabulary provides terms that are used as entity types, an authority file supplies identifiers for the actual entities, such as a specific person, place, or work. For the purposes of LINCS, an authority file is primarily a source of URIs.
Those URIs reach LINCS data in two ways:
- Reused directly. The external URI serves as the identifier for the entity itself, so the statements describing that entity are made with the authority's URI as their subject, and no LINCS URI is minted for it.
- Linked with
owl:sameAs. The entity keeps a LINCS-minted URI, and anowl:sameAsstatement declares it equivalent to the corresponding record in the authority file. LINCS data uses this pattern widely, most often pointing at Wikidata, VIAF, and the Getty vocabularies.
For more information about how LINCS assigns URIs to entities, see Entity Identifiers and URI Minting. The distinction between vocabularies and authority files is not always clear-cut, and in some cases, a single resource may serve both purposes.
A Note on Wikidata
Wikidata occupies a particular position in LINCS. Because it is crowdsourced, its structure is subject to frequent changes and it is not always consistent. LINCS matches data against Wikidata and uses its terms widely, but treats it as a collection of terms rather than an established vocabulary.
The hierarchies laid out by the Wikidata database structure are the responsibility of the Wikidata community and not reviewed or endorsed by LINCS. This should not stop you from using Wikidata, which remains a useful source of URIs for concepts that exist nowhere else, and the easiest place to add a term when one is missing, since it accepts new terms without prior approval.
However, where a reliable domain-specific vocabulary exists, you should prefer it. For example, if you need terms for LGBTQIA+ concepts, use Homosaurus rather than Wikidata: Homosaurus has a dedicated collective that meets regularly, updates terms, and conducts community consultation. Its narrower focus makes it better maintained and more authoritative within that domain.
Choosing a Vocabulary
Where to Start
Work through these options in order, and stop at the first one that meets your data’s needs:
- A term already used in other LINCS datasets. This is the strongest option for discoverability. See Vocabularies Currently Used in LINCS.
- A term from a LINCS-hosted vocabulary. See LINCS-hosted Vocabularies.
- A term from a reliable external vocabulary. See Criteria for Selecting Vocabularies.
- A new term contributed to an external vocabulary that accepts additions, such as Wikidata. See Adding Terms to External Vocabularies in the policy.
- A new term or vocabulary hosted by LINCS. See Contributing to LINCS-hosted Vocabularies.
Reusing a term that other LINCS datasets already use makes your data findable alongside theirs. If two datasets both use the same URI for ceramic, entities from both appear together in a single search. Several LINCS datasets type the titles of creative works with http://vocab.getty.edu/aat/300417193 from the Getty Art & Architecture Thesaurus, so a single query against the LINCS triplestore returns titles from all of them at once.
The diagram below sets out the same sequence as a series of questions.
Finding Vocabularies
The Linked Open Vocabularies (LOV) project is a good starting point for searching for terms from over 900 vocabularies. The Canadian Heritage Information Network (CHIN) provides a useful guide to vocabularies for cultural heritage; see Vocabulary (data value standards).
Two further resources:
- The DLF Inclusive Metadata Toolkit collects guidance and resources for choosing and applying vocabularies inclusively.
- The LINCS Vocabulary Browser shows, for each LINCS-hosted vocabulary and each individual term, which datasets already use it. See Checking Usage of Specific Terms.
The policy's Finding External Vocabularies section also points to guidance on obtaining dereferenceable URIs for vocabulary terms.
Criteria for Selecting Vocabularies
Any external vocabulary you adopt has to meet the conditions set out in Policy for External Vocabularies: a unique, persistent, dereferenceable URI for every term, labels and definitions that meet your semantic requirements, evidence of ongoing maintenance and adoption in the wider Linked Open Data community, and compatibility with LINCS ethics policies. Where more than one candidate meets those conditions, weigh them against the following criteria.
| Criterion | What to ask |
|---|---|
| Interoperability | Is this vocabulary already used in LINCS datasets? Is it widely used beyond LINCS? |
| Domain alignment | Was the vocabulary built for your subject matter, or are you borrowing a term from a general-purpose source? |
| Authority | Is there a named institution or editorial body behind it, and is its editorial process transparent? |
| Structure vs. cherry-picking | Are you adopting a coherent hierarchy, or taking isolated terms from one? |
| Extensibility | If a term you need is missing, can you get one added, and how long does that take? |
| Maintenance and longevity | Is there evidence of recent activity, and a reason to expect the URIs to still resolve in ten years? |
| Quality | Are the definitions clear, and do they actually mean what the label suggests? See Comparing Similar Terms. |
Comparing Similar Terms
Two terms with near-identical labels can denote very different concepts. Read the definition and check where the term sits in its hierarchy before adopting it.
For example, the Wikidata term Americans (http://www.wikidata.org/entity/Q846570) refers specifically to “citizens and nationals of the United States of America,” and is declared an instance of human population, nationality, and citizenship. The Getty AAT term American (North American) (http://vocab.getty.edu/aat/300107956) refers to the “context of or associated specifically with the modern political entity of the United States of America,” and is a subclass of the Styles and Periods Facet, which covers “art and architecture styles, historical periods, art movements, cultures, and ethnicities.”
Vocabularies Currently Used in LINCS
The following is not an endorsement of any particular vocabulary, but rather, an overview of what LINCS datasets actually use, so that you can reuse existing choices where they suit your data. You are free to adopt a vocabulary that does not appear here.
LINCS-hosted Vocabularies
LINCS-hosted vocabularies are created collaboratively by data stewards and LINCS when existing vocabulary terms cannot provide the semantic specificity a dataset requires. They support the linking of data related to cultural identities and activities, broadly defined, to complement other linked data vocabularies, and they aim to support diversity, inclusivity, and context in the representation of human culture online. These SKOS vocabularies are open for use by others, and LINCS welcomes further contributions, collaboration, and reuse.
| Vocabulary | Description |
|---|---|
| Biography | Biographical description, from naming conventions and education to human reproduction, places, and spatial relationships. |
| Canadian Writing Research Collaboratory (CWRC) | The lives and careers of writers. A legacy vocabulary: it has been broken into the component vocabularies listed here, which should be used instead. |
| Context | The discursive context of an assertion, statement, or description, used for instance to type web annotations. Ranges from birth to politics to intimate relationships. |
| Early Modern London Place Type | Place types for described locations in early modern London. |
| Editing | Digital editing, covering both born-digital content and digital scholarly editions. |
| Event | Events classified by type and significance, many of them biographical. |
| Genre | The form, medium, and genre of cultural objects, particularly but not exclusively written ones. |
| Identity | Social identities such as race or colour, ethnicity, gender, language, sexuality, politics, and religion, treated as shifting and culturally constructed categories. |
| Injuries and Illnesses | Health problems and causes of death, for historical or cultural analysis where specific information is often unavailable. |
| Occupation | Vocational, career, employment, professional, and leisure activities that people habitually engage in or have engaged in. |
| Personal Relations | Relationships between people, and the roles that go with them, for biographical and prosopographical description. |
| Writing | Writing and writing careers: production context, reception, and textual features. Still in progress and largely incomplete. |
Where LINCS-hosted vocabularies live, and who is responsible for maintaining them, is set out in Accessibility & Persistence and Responsibilities in the policy.
For how to propose a new term, request a change, or create a new LINCS-hosted vocabulary, see LINCS-hosted Vocabularies.
External Vocabularies Used in LINCS
The external vocabularies most commonly used across LINCS datasets are the following.
| Vocabulary | What it covers |
|---|---|
| Getty Art & Architecture Thesaurus (AAT) | Art, architecture, and material culture: object types, materials, techniques, styles, and periods. The most heavily used external vocabulary in LINCS. |
| Library of Congress | Subject headings, genre and form terms, performance mediums, and relator roles, drawn from the LoC authorities. |
| Wikidata | General-purpose coverage, useful for concepts that exist nowhere else. See A Note on Wikidata before adopting its terms. |
| Homosaurus | LGBTQIA+ terminology, maintained by a dedicated collective with community consultation. |
| VIAF | Name authority records for people and organizations, used to identify individuals rather than to type them. |
| DBpedia | Structured terms extracted from Wikipedia. |
| Nomenclature | Object naming for museum cataloguing, published in English and French. |
| OCLC FAST | Faceted subject terminology derived from Library of Congress Subject Headings. |
| Schema.org | General-purpose types for describing web content. |
Vocabulary Usage by Dataset
The view below is generated from the triplestore each time this page loads, so it always reflects the current data. Each card corresponds to one dataset and reports two sets of sources: the vocabularies it draws on, with the number of distinct terms taken from each, and the authority files it draws on, with the number of distinct identifiers taken from each. Use it to find which sources are established in a domain close to your own.
The two counts follow the distinction drawn in What Counts as a Vocabulary and What Counts as an Authority File. A vocabulary term is counted when it is used to type an entity: when it is the object of a crm:P2_has_type statement, or is itself declared a crm:E55_Type or a skos:Concept, which is the same definition the project dataset pages use. An authority identifier is counted when an external URI identifies an entity directly, or when a LINCS entity is linked to one with owl:sameAs.
Loading current vocabulary and authority usage from the triplestore… (0 of 16)
In the view above, a vocabulary appears once it contributes more than one term, while an authority appears once it contributes at least ten identifiers, since datasets draw on far more identifier sources than vocabularies.
Checking Usage of Specific Terms
To see what a single dataset uses, consult its own page. Every project dataset page carries a “Vocabulary Terms Used By” section that queries the triplestore as the page loads and lists the namespaces the dataset draws on, the number of distinct terms taken from each, and the terms themselves. Alongside it the page reports the CIDOC CRM classes the dataset uses and a summary of its contents. The Canadian Centre for Ethnomusicology page shows what this looks like.
Each dataset’s Application Profile then explains the vocabulary choices behind those figures, along with queries for viewing the terms it uses.
Every LINCS-hosted vocabulary page in the Vocabulary Browser carries a “Vocabulary Usage by Dataset” section at the bottom, listing which datasets use the vocabulary, which terms they use, and how often. The same section appears on individual term pages, so you can check the uptake of a single term before adopting it. Scroll to the bottom of the Biography vocabulary to see it in action.
Using Vocabulary Terms in Your Data
Where Vocabularies Fit in the Conversion Workflow
Vocabulary work is spread across three steps of the conversion workflow:
| Step | What happens to vocabularies |
|---|---|
| Match Entities | You find existing URIs for the terms in your data. The Matching Vocabulary Terms section covers this directly: the concepts and techniques for matching entities apply to vocabulary terms as well. OpenRefine and VERSD streamline the process, but you may need to look beyond the vocabularies reachable from LINCS tools to find terms whose labels or definitions suit your data. |
| Develop Conceptual Mapping | LINCS works with you to determine how vocabulary terms will be integrated into your data. This is where each vocabulary term’s rdf:type is decided. |
| Validate and Enhance | You retrieve official labels for the external terms you used and add them to your dataset. The Linked Data Enhancement API supports this. |
Note that LINCS documentation now says entity matching where older material said reconciliation; the two refer to the same activity.
Minimum Requirements for Every Term
As with any entity in LINCS data, each vocabulary term must at minimum be declared with an rdfs:label and an rdf:type, and that declaration must be included directly in your contributed dataset. This holds for all three kinds of term: existing LINCS-minted terms, external terms, and terms LINCS mints during conversion.
- For an existing term, retrieve the official label and type from the authority file. See Validate and Enhance and the Linked Data Enhancement API.
- For a term minted during conversion, the label is supplied by the data contributors.
Ideally rdfs:label values are provided in both English and French, and other languages are encouraged.
Adding Your Own Labels
You may add additional rdfs:label values to external vocabulary terms and to any LINCS-minted entity or term, for labels specific to your project. You may also use skos:altLabel, skos:prefLabel, or skos:hiddenLabel for the same purpose. The project’s preferred wording is then carried with the data, without changing the identity of the term.
Types of Vocabulary Terms
LINCS distinguishes three kinds of vocabulary term. All three meet the definition of a vocabulary term given earlier.
| Type | Example |
|---|---|
| LINCS-namespace terms defined within a LINCS-hosted structured vocabulary. Each of these terms may or may not be used elsewhere in LINCS data. | editor (http://id.lincsproject.ca/occupation/editor), from the Occupation vocabulary. |
| LINCS-namespace terms used in LINCS data that do not come from a LINCS-hosted structured vocabulary. | Yellow Nineties identifier (http://id.lincsproject.ca/4otAZj1kQpK), minted so that identifiers specific to the Yellow Nineties dataset could be typed as such. |
| Any term used in LINCS data that does not have a LINCS namespace, does not belong to a LINCS-hosted structured vocabulary, but does meet the LINCS definition of a vocabulary term. | paintings (visual works) (http://vocab.getty.edu/aat/300033618), from the Getty Art & Architecture Thesaurus. |
How LINCS URIs for Vocabulary Terms Are Created
LINCS creates new URIs for vocabulary terms in three situations:
- During the creation of a LINCS-hosted vocabulary. See Proposing a New LINCS-hosted Vocabulary.
- When adding a term to an existing LINCS-hosted vocabulary. See Submitting a New Term to an Existing Vocabulary.
- While converting a dataset, when the term is not being added to a structured vocabulary. Here the term is treated like any other entity in LINCS data and receives the same random UID URI format. It is still a vocabulary term, because of how it connects to other entities in the data.
Terms in a LINCS-hosted structured vocabulary have a URI of the form http://id.lincsproject.ca/{vocabName}/{termId}, where {vocabName} is unique to each structured vocabulary and {termId} can be any text unique to that term within it, including ordinary English words. Both are agreed for each vocabulary during its creation, between the data contributors and LINCS.
Terms minted during conversion instead take the general form used for any LINCS entity, and the temporary URIs assigned before a dataset is published follow their own convention. Both are covered in Entity Identifiers and URI Minting, which is the authoritative account of how LINCS mints and maintains URIs, including its commitment to deprecating rather than deleting them.
Exploring Vocabularies
Vocabulary Browser
The Vocabulary Browser is a Skosmos instance that lets you browse LINCS-hosted vocabularies alphabetically, hierarchically, and by grouping, in English and French. It is the best starting point for seeing what a LINCS-hosted vocabulary contains and how its terms relate to one another, and it carries the usage statistics described in Checking Usage of Specific Terms.
The Vocabulary Browser shows only LINCS-hosted vocabularies, and only their SKOS structure. See SKOS and CIDOC CRM for how the two layers differ.
ResearchSpace
In ResearchSpace, vocabulary terms are typed using the crm:E55_Type and skos:Concept classes, and can be found using the search bar on the homepage and in the site header. There is no way to browse vocabulary terms exclusively: instead, vocabulary terms appear as facets across all search portals, where they filter results by subject. In the knowledge map you can search for a vocabulary term and then explore the entities connected to it, which is an effective way to discover material related to a term of interest.
SPARQL
LINCS-hosted vocabularies are loaded into the Fuseki triplestore in the /skosmos and /lincs datasets, and appear as named graphs in the LINCS Blazegraph triplestore behind ResearchSpace. The following pre-built queries open in YASGUI:
| Query | Returns |
|---|---|
| List of Vocabularies | Every vocabulary in the triplestore, with English label and description. Uses the /skosmos endpoint. |
| All Terms from a Vocabulary | Every term in one vocabulary, with label and definition. Change the bind(...) line to target a different vocabulary; the example uses Occupation. |
| Properties of a Term | Every property asserted about a single term. Change the bind(...) line; the example uses occupation:stationer. |
References and Resources
- Linked Open Vocabularies (LOV). https://lov.linkeddata.es/dataset/
- Canadian Heritage Information Network, “Vocabulary (data value standards).” https://www.canada.ca/en/heritage-information-network/services/collections-documentation-standards/chin-guide-museum-standards/vocabulary-data-value.html
- Digital Library Federation, “Inclusive Metadata Toolkit.” https://osf.io/yf96h
- Program for Cooperative Cataloging, “Formulating and Obtaining URIs.” https://www.loc.gov/aba/pcc/bibframe/TaskGroups/formulate_obtain_URI_guide.pdf
- CIDOC CRM Special Interest Group, “CIDOC Conceptual Reference Model.” https://www.cidoc-crm.org/
- W3C, “SKOS Simple Knowledge Organization System Reference.” https://www.w3.org/TR/skos-reference/
- LINCS Fuseki SPARQL endpoint, queried by the usage view on this page. https://fuseki.lincsproject.ca/
Document Details
Version: 0.1 (draft)
Authors: [To be named]
Contributors: the LINCS Project team
Last Updated: 2026-08-15
Released: [Unreleased]