HED (Hierarchical Event Descriptors) is a standardized vocabulary and supporting infrastructure for annotating experimental metadata and mapping it into the experimental timeline. See HED resources for more information about the HED project.
HED itself consists of a standard vocabulary the (HED standard schema) and specialized subfield vocabularies (HED library schemas). These vocabularies are developed and maintained in the hed-schemas GitHub repository.
The HED ontology is a representation of the HED schemas as a formal ontology of the HED information space. Releases of new HED schemas trigger a generation of a new HED ontology in this repository (hed-ontology), and maintainers of this repository do a new release. The correspondence between the HED schemas and HED ontology is explained more fully in The HED ontology chapter of the **hed-specification.
Each HED entity in the HED information space has a globally unique identifier
of the form HED_xxxxxxx where xxxxxxxx is a 7-digit number.
The identifier namespace is assigned as follows:
| Schema | ID Range | Description |
|---|---|---|
| Structure | 0000001 - 0009999 | Structure elements for HED ontology. |
| Standard | 0010001 - 0039999 | Standard annotation of experiments. |
| Score | 0042000- 0059999 | Annotation by clinical neurologists. |
| Lang | 0062000 - 0079999 | Annotation of language stimuli. |
| Version | Contains | Files | Description |
|---|---|---|---|
| 2024-06-10 | 8.3.0 | hed.owlhed-standard.owl |
Contains only the standard schema |
These are the PURL values relative to the
| PURL | Relative path |
|---|---|
| https://purl.org/hed/hed.owl | ./hed.owl |
| https://purl.org/hed/hed-standard.owl | ./hed-standard.owl |
| https://purl.org/hed/releases/2024-06-10/hed.owl | ./releases/2024-06-10/hed.owl |
| https://purl.org/hed/releases/2024-06-10/hed-standard.owl | ./releases/2024-06-10/hed-standard.owl |
In general, posts to our GitHub issue tracker are recommended, however, if needed, you can contact the ontology curator by sending an e-mail mailto:hed-maintainers@gmail.com.
