- From: Dan Brickley <danbri@google.com>
- Date: Mon, 30 Sep 2013 20:27:44 +0100
- To: Karen Coyle <kcoyle@kcoyle.net>
- Cc: "Wallis,Richard" <Richard.Wallis@oclc.org>, Guha <guha@google.com>, W3C Vocabularies <public-vocabs@w3.org>
On 30 September 2013 20:24, Karen Coyle <kcoyle@kcoyle.net> wrote: > > > On 9/30/13 11:24 AM, Dan Brickley wrote: >> >> On 30 September 2013 19:15, Wallis,Richard <Richard.Wallis@oclc.org> >> wrote: >>> >>> Is this not why 'additionalType' was added to Thing? >> >> >> Yes: Microdata has trouble with the idea of describing an item using >> multiple independently defined types: >> >> " Multiple types defined to use the same vocabulary can be given for a >> single item by listing the URLs as a space-separated list in the >> attribute' value. An item cannot be given two types if they do not use >> the same vocabulary, however." -- >> >> http://www.whatwg.org/specs/web-apps/current-work/multipage/microdata.html#typed-items >> >> Rather than trying to gradually turn Microdata into something that it >> isn't (i.e. back into RDFa), the schema.org team decided instead to >> add the additionalType property. > > > I had understood the "additionalType" as mainly having a function of > categorization -- this thing is both an apple and a fruit. Does the use of > an additionalType that is a schema.org type provide access to all of the > properties of the additionalType? It is purely another way of writing rdf:type. Any pair of things that are related by rdf:type could equally well be described as being related by schema:additionalType. In the sense that RDF's types/classes are useful for categorisation, then so is this mechanism. But maybe there's a subtle difference in how you're using the word 'categorize' that I'm not picking up on? Dan
Received on Monday, 30 September 2013 19:28:12 UTC