The NIST Extensible Resource Data Model (NERDm): JSON schemas for rich description of data resources

The NIST Extensible Resource Data Model (NERDm) is a set of schemas for encoding in JSON format metadata
that describe digital resources. The variety of digital resources it can describe includes not only
digital data sets and collections, but also software, digital services, web sites and portals, and
digital twins. It was created to serve as the internal metadata format used by the NIST Public Data
Repository and Science Portal to drive rich presentations on the web and to enable discovery; however, it
was also designed to enable programmatic access to resources and their metadata by external users.
Interoperability was also a key design aim: the schemas are defined using the JSON Schema standard,
metadata are encoded as JSON-LD, and their semantics are tied to community ontologies, with an emphasis
on DCAT and the US federal Project Open Data (POD) models. Finally, extensibility is also central to its
design: the schemas are composed of a central core schema and various extension schemas. New extensions
to support richer metadata concepts can be added over time without breaking existing applications.