Difference between rdf:seeAlso and rdfs:seeAlso

问题:

What is the difference between rdf:seeAlso and rdfs:seeAlso?

When I can use rdf:seeAlso and when I can use rdfs:seeAlso?

Can you do any examples?

回答1:

First, note that rdf and rdfs are prefixes commonly used to reference the RDF syntax and RDF schema vocabularies respectively. The rdf is typically used for http://www.w3.org/1999/02/22-rdf-syntax-ns#, so that rdf:seeAlso would expand to http://www.w3.org/1999/02/22-rdf-syntax-ns#seeAlso. However, if you follow the vocabulary reference, you won't find a term defined for seeAlso. The RDF syntax is used for basic types such as rdf:type, rdf:XMLLiteral, and rdf:langString. the RDF Schema vocabulary is typically bound to the rdfs prefix, and is at http://www.w3.org/2000/01/rdf-schema#. It is mostly used to define terms useful in performing simple reasoning over RDF graphs, such as rdfs:subClassOf, rdfs:domain, and rdfs:range.

In reality, the terms defined between the two vocabularies end up being in arbitrary locations, and on retrospect, there should have probably been just a single vocabulary definition and a more easily understood location (such as http://www.w3.org/ns/rdf#), but too late for that now.

Why use rdfs:seeAlso is unclear. The description says "Further information about the subject resource.", but there's rules defined for how to use it. In Linked Data, it can be used to do just what it says, and a hypothetical linked data client might dereference IRI values of rdfs:seeAlso to find out more information that might be useful.

You can find out more in the RDF Concepts document and other publications of the RDF Working Group.

回答2:

What is the difference between rdfs:seeAlso and rdfs:isDefinedBy?

These are defined pretty clearly in the specification:

5.4.1 rdfs:seeAlso

rdfs:seeAlso is an instance of rdf:Property that is used to indicate a resource that might provide additional information about the subject resource.

A triple of the form:

S rdfs:seeAlso O

states that the resource O may provide additional information about S. It may be possible to retrieve representations of O from the Web, but this is not required. When such representations may be retrieved, no constraints are placed on the format of those representations.

5.4.2 rdfs:isDefinedBy

rdfs:isDefinedBy is an instance of rdf:Property that is used to indicate a resource defining the subject resource. This property may be used to indicate an RDF vocabulary in which a resource is described.

A triple of the form:

S rdfs:isDefinedBy O

states that the resource O defines S. It may be possible to retrieve representations of O from the Web, but this is not required. When such representations may be retrieved, no constraints are placed on the format of those representations. rdfs:isDefinedBy is a subproperty of rdfs:seeAlso.

When I can use rdfs:seeAlso and when I can use rdfs:isDefinedBy? Can you do any examples for me?

You can use these whenever they're appropriate. Just include the appropriate triples in your data. I don't think there's really a whole lot of need for examples in this case; if something's a related resource, add a seeAlso link. If something has a definition by another resource, add a isDefinedBy link. Note that last bit, "rdfs:isDefinedBy is a subproperty of rdfs:seeAlso". That means that whenever you assert that "x rdfs:isDefinedBy y", you're implicitly asserting that "x rdfs:seeAlso y".

回答3:

rdfs:seeAlso is an instance of rdf:Property that is used to indicate a resource that might provide additional information about the subject resource.

rdf is the original resource description framework whereas rdfs provides the schema information