Schema.org classes and types of classes

[marcolarosa]

I've been updating the scraper that produces a describo profile from schema.org. In a nutshell, the scraper:

• downloads the latest jsonld file: https://schema.org/version/latest/schemaorg-current-http.jsonld
• extracts all things of @type='rdfs:Class'
• maps the properties of each class into it as a set of inputs.

Doing this yields 866 classes and 1385 properties. However, when I iterate over the ro-crate context from https://www.researchobject.org/ro-crate/1.1/context.jsonld I find there are 2628 entries in it.

Looking closer we find that some of the things in the context are not actually classes or properties (365 of these other things) in schema.org. For example:

https://schema.org/PhysicalActivityCategory is a class with parents Enumeration, Intagible, Thing in that order.

However, https://schema.org/AerobicActivity is not a class but rather:

"@type": "http://schema.org/PhysicalActivityCategory"

From the docs for AerobicActivity we see A member value for enumeration type: PhysicalActivityCategory.

And AerobicActivity has no properties.

I don't understand how this works and I'm not sure what I am to produce in the profile for this to make sense. Any guidance would be most appreciated.