Ontology for theme of a text

Question

I'm looking for an ontology that describes the theme of a text (eg. "finance", "leisure"). A text can have multiple themes. Preferably the ontology would also have room to store a match percentage:

{
    "theme": "finance",
    "match": "96.2%"
}

I looked at foaf:theme but it appears to be deprecated and doesn't allow any extra properties.

Answer 1

• For a straight theme, use <doc> dc:subject "foo"
• To add confidence, you can use RDF*:
  • << <doc> dc:subject "foo" >> my:confidence 0.962

But maybe RDF* is an overkill.

• You can use the NIF (NLP Interchange Format) ontology. Use its:taIdentRef to point to the theme (has to be a URL), and I think its:taIdentConf is for the confidence
• Another option is to use the Web Annotation ontology. Put the doc URL in oa:hasTarget, the theme in oa:hasBody and the confidence in . This is how Ontotext's TAG works (disclaimer: I work for them)