RDFS - declaring properties

Question

Hi, I am very new to working with semantic data and have a quick question that i cant find an answer to.

When creating an rdf schema are you essentially creating a class as per OOP i.e. declaring all properties etc that are valid. If this is the case then say I want a property called 'title' which I actually intend on using dcterms:title do I have to specifically declare this to be a member of my rdf class in the schema and declare it as a sub property of dcterms:title. Or, do I omit this from the schema and simply use it when creating the rdf instance?

I hope this makes sense and thank anyne in advance for any advice they can offer on this.

Answer 1

When creating an rdf schema are you essentially creating a class as per OOP i.e. declaring all properties etc that are valid.

This is a common misconception, and wrong. It's perfectly understandable, however, and invited by the use of the term 'schema' which in XML and relational databases can suggest a definition or constraint on the data.

The W3C recommendation is called 'RDF Vocabulary Description Language 1.0: RDF Schema', which is an attempt to get away from the 'schema' word, and suggest what rdfs does: describe vocabularies. RDF 'schemas' are just collections of descriptions of classes and properties.

So the short answers are: 'do I have to specifically declare this to be a member of my class' no. 'do I omit this from the schema and simply use it when creating the rdf instance' yes, that's fine.