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Re: new itemscope or not?

From: Martin Hepp <martin.hepp@ebusiness-unibw.org>
Date: Tue, 11 Sep 2012 15:49:08 +0200
Cc: public-vocabs@w3.org
Message-Id: <8FB1754F-5BFB-403B-AC88-6DECD343FA50@ebusiness-unibw.org>
To: Cord Wiljes <cwiljes@cit-ec.uni-bielefeld.de>
My understanding is that schema:url is intended to be equivalent to foaf:page. Note that schema.org aims at typical Web developers, and IMO, for them "url" may be a very appropriate name for a property that holds the URL (sic!) of a Web resource related to the entity.

Even in the bizarre world of the Pedantic Web Group, the name url for the property should be fine, because all valid values for this properties will be URLs in the sense of URIs that serve as locators for representations. The usage of "url" does not imply that it has to be the URL of the representation of the subject entity. It can also be the URL of a representation that describes the entity.


> Description: URL of the item.

may be an acceptable wording for the property for broad audiences.

PS: If you refer to rdfs:seeAlso with see also in

> Or in other words: "url" means something rather general: "There is a web document related to the resource that can be retrieved at this url." Essentially its just a "see also" to a document on the web.

then it should be noted that the valid range for rdfs:seeAlso is arguably limited to RDF representations, see the lengthy thread that started with this email:


Also, see


for the conclusion.

On Sep 10, 2012, at 12:16 PM, Cord Wiljes wrote:

> The schema.org specification seems to support Jeff's interpretation of the property "url" as "the WWW-address where an electronic copy of the thing that s described can be downloaded". From http://www.schema.org/Thing:
> Property: url
> Expected Type: URL
> Description: URL of the item.
> Only something that can be downloaded (an information resource) can have a URL. So schema.org's property "url" should only be available for "CreativeWork", not for "Thing" as it is right now. A person for example can't have a url. A person can have a website (which is an information resource) and this website has an url. But then I cannot find any property like "website" or "homepage" for any of schema.org's classes. Combined with the fact that "url" is avalable for class "Thing" (i.e. for everything) I suppose that "url" is in fact used ambiguosly:
> A book can have a url where you can download the book's text.
> A person can have a url where you find information about this person.
> Or in other words: "url" means something rather general: "There is a web document related to the resource that can be retrieved at this url." Essentially its just a "see also" to a document on the web.
> Cord
> Am 08.09.2012 04:14, schrieb Young,Jeff (OR):
>> If I was Godz, I would NOT assume they are the same thing. I would use
>> schema:url thusly for those decreasingly rare situations where somebody
>> (especially a remote observer) wants to describe something that is
>> honest-to-godz located on the Web. For example:
>> @prefix observer: <http://example.org/observer/> .
>> observer:12345 a <http://purl.org/library/Thesis>;
>> 	schema:name "Architectural Styles and the Design of
>> Network-based Software Architectures";
>> 	schema:author <http://viaf.org/viaf/26681119>;
>> 	schema:url
>> <http://www.ics.uci.edu/~fielding/pubs/dissertation/top.htm>.
>> As a matter of principle, Roy's (HTML) thesis COULD be upgraded to be
>> self-describing with some hidden markup (either RDFa 1.1 or Microdata)
>> and a trivial Apache rewrite (303 redirect) upgrade to www.ics.ici.edu
>> to replace the observer URI.
>> OTOH, if somebody decides that schema:url should be treated the same as
>> "itemid" (Microdata), "resource" (RDFa Lite 1.1), "rdf:about" (RDF/XML),
>> etc. then schema:url is a wasted opportunity and we (i.e. the pedantic
>> observers of reality) would need to find a new vocabulary term fill this
>> void.
>> Jeff
>>> -----Original Message-----
>>> From: Jeni Tennison [mailto:jeni@jenitennison.com]
>>> Sent: Friday, September 07, 2012 3:15 PM
>>> To: Ed Summers
>>> Cc: Dawson, Laura; Thad Guidry; public-vocabs@w3.org
>>> Subject: Re: new itemscope or not?
>>> On 7 Sep 2012, at 20:03, Ed Summers wrote:
>>>> It would be interesting to know if the HTML spec allowed multiple
>>>> identifiers, similar to how other HTML attributes work:
>>> "The itemid attribute, if specified, must have a value that is a valid
>>> URL potentially surrounded by spaces."
>>> http://www.w3.org/TR/microdata/#attr-itemid
>>> So that would be 'no', not according to spec.
>>> I've often wondered whether the schema.org 'url' property is meant to
>>> be synonymous with itemid. I'm not sure what happens in schema.org
>>> interpreters when you specify one/other/both/multiple urls...
>>> Jeni
>>> --
>>> Jeni Tennison
>>> http://www.jenitennison.com
> -- 
> Cord Wiljes
> Semantic Computing Group
> Excellence Cluster - Cognitive Interaction Technology (CITEC)
> Bielefeld University
> Phone: +49 521 106 12036
> Mail: cwiljes@cit-ec.uni-bielefeld.de
> WWW: http://www.sc.cit-ec.uni-bielefeld.de/people/wiljes
> Room H-123
> Morgenbreede 39
> 33615 Bielefeld

martin hepp
e-business & web science research group
universitaet der bundeswehr muenchen

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Received on Tuesday, 11 September 2012 13:49:40 UTC

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