OpenAlex technical documentation
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      • Work object
        • Authorship object
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      • Source object
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      • Institution object
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      • Topic object
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      • Publisher object
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      • Funder object
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    • 🌎Geo
      • Continents
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    • Concepts
      • Concept object
      • Get a single concept
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    • Aboutness endpoint (/text)
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  1. API Entities

Concepts

PreviousRegionsNextConcept object

Last updated 10 months ago

These are the original OpenAlex Concepts, which are being deprecated in favor of . We will continue to provide these Concepts for Works, but we will not be actively maintaining, updating, or providing support for these concepts. Unless you have a good reason to be relying on them, we encourage you to look into instead.

Concepts are abstract ideas that works are about. OpenAlex indexes about 65k concepts.

  • Get all the concepts used by OpenAlex:

The for OpenAlex concepts is the Wikidata ID, and each of our concepts has one, because all OpenAlex concepts are also Wikidata concepts.

Concepts are hierarchical, like a tree. There are 19 root-level concepts, and six layers of descendants branching out from them, containing about 65 thousand concepts all told. This concept tree is a modified version of .

You can view all the concepts and their position in the tree . About 85% of works are tagged with at least one concept (here's the ).

How concepts are assigned

Each work is tagged with multiple concepts, based on the title, abstract, and the title of its host venue. The tagging is done using an automated classifier that was trained on MAG’s corpus; you can read more about the development and operation of this classifier in You can implement the classifier yourself using .

A score is available for each , showing the classifier's confidence in choosing that concept. However, when assigning a lower-level child concept, we also assign all of its parent concepts all the way up to the root. This means that some concept assignment scores will be 0.0. The tagger adds concepts to works written in different languages, but it is optimized for English.

Concepts are linked to works via the property, and to other concepts via the and properties.

What's next

Learn more about what you can do with concepts:

Topics
Topics
https://api.openalex.org/concepts
the one created by MAG
as a spreadsheet here
breakdown of concept counts per work
Automated concept tagging for OpenAlex, an open index of scholarly articles.
our models and code
The Concept object
Get a single concept
Get lists of concepts
Filter concepts
Search concepts
Group concepts
Canonical External ID
ancestors
related_concepts
concept in a work
concepts