Linked Art API: Shared Concept References

Last refreshed: 2026-07-06

Source: Types / Concepts shared structure, part of Linked Art API 1.0, published under CC BY 4.0. This is a project summary; the upstream page is authoritative.

Purpose

Concept references, usually called Types in Linked Art, connect resource descriptions to controlled vocabularies such as the Getty Art and Architecture Thesaurus. They are used throughout the model for classification, language, material, currency, measurement units, techniques, subjects, and assignment values.

For full concept records, use the Concepts endpoint(concepts.md). This shared structure is the compact embedded reference form used inside other records.

Required Shape

A concept reference includes:

• `id`: required URI identifying the concept.
• `type`: required. Must be one of `Type`, `Currency`, `Language`, `Material`, or `MeasurementUnit`.

Recommended Fields

• `_label`: developer-facing label.

Optional Fields

• `equivalent`: references to equivalent external resources.
• `notation`: commonly used notation or identifier strings, especially language tags on `Language`.
• `classified_as`: meta-classifications for the concept, following the same `Type` requirements.

Concept Classes

• `Type`: generic concept for classifications, techniques, styles, genres, subjects, and meta-types.
• `Language`: human-spoken language, such as Spanish.
• `Material`: material that makes up a physical thing, such as gold.
• `Currency`: currency used by a monetary amount, such as the Euro.
• `MeasurementUnit`: unit used by a dimension, such as inches.

Common Incoming Relationships

• `classified_as`: almost every entity can be classified by a `Type`.
• `technique`: activities can have techniques modeled as `Type`.
• `influenced_by`: activities can be motivated by a `Type`.
• `about`: textual and visual works can have conceptual subjects.
• `assigned`: attribute assignments can assign a classification.
• `language`: linguistic content uses `Language`.
• `currency`: monetary amounts use `Currency`.
• `unit`: dimensions use `MeasurementUnit`.
• `made_of`: physical objects use `Material`.

Meta Museum Notes

Meta Museum already preserves compact concept references and full concept records. Existing coverage proves `Type`, `Material`, `Language`, `Currency`, and `MeasurementUnit` remain valid concept classes; records preserve `classified_as`, `language`, `unit`, `equivalent`, `notation`, `broader`, and concept-scheme membership without flattening controlled vocabulary references into plain strings. The important project rule is to preserve meta-classification, such as a painting Type classified as Type of Work.

Test Ideas

• Preserve all allowed concept reference classes: `Type`, `Currency`, `Language`, `Material`, and `MeasurementUnit`.
• Preserve `classified_as` meta-types on concepts, such as painting classified as Type of Work.
• Preserve `notation` for language tags.
• Preserve concept references in `classified_as`, `technique`, `influenced_by`, `about`, `assigned`, `language`, `currency`, `unit`, and `made_of`.
• Preserve `equivalent[]` for external vocabulary reconciliation without treating labels as stable identifiers.