- From: Brian McBride <bwm@hplb.hpl.hp.com>
- Date: Tue, 25 Mar 2003 17:13:43 +0000
- To: Charles McCathieNevile <charles@sidar.org>, www-rdf-comments@w3.org, wai-xtech@w3.org, Dave Beckett <dave.beckett@bristol.ac.uk>
Forgot to change the subject line. Brian At 16:35 25/03/2003 +0000, Brian McBride wrote: >Hi Chas, > >thanks for the comments. > >At 15:43 12/03/2003 +0100, Charles McCathieNevile wrote: > >>This was originally sent privately to Brian McBride as accessibility >>comments - just making sure people see it. >> >>cheers >> >>Chaals >> >>-- >>Charles McCathieNevile Fundacion Sidar >>http://www.sidar.org/ >> >>-------- Original Message -------- >> >>There are two issues. The first is the lack of a standardised >>"abouteachprefix" in RDF. > >I've recorded this as a comment on the syntax doc: > > http://www.w3.org/2001/sw/RDFCore/20030123-issues/#chas-01 > >The WG will consider this comment and get back to you in due course. > >Brian > >>The second, and I think more serious, is that there >>is no defined way to talk about a view of a document, where those views are >>defined by using a URIRef for a particular MIME type. >> >>I have tried to lay them out below, but am not writing terribly clearly >>today, so i hope this is enough to go on with. It might be useful to try and >>talk about this some more tonight or tomorrow - I will be around. I thought >>it was better to send something sooner than the perfect version later. >> >>(and finally due to various process wierdness please note that this email is >>supposed to be from me as an invited expert to the WAI PF group, representing >>La Fundaciòn Sidar, as charles@w3.org) >> >>cheers >> >>Chaals >> >>Issue 1 - aboutEachPrefix >> >>"aboutEachPrefix" seems to be a particular instance of a class of things. >>There are many cases where people want to talk about a set of objects without >>having to enumerate the list: >> >>- things in a particular namespace (the original aboutEachPrefix case) are >>published by the owner of that namespace; >> >>- the infinite set of times within a particular range for one calendar fall >>within the range of a particular date in another calendar (think about how >>many nameable times on the 1st of Ramadan 1476AH fall on a particular day in >>the gregorian calendar, as measured in Paris) >> >>- the homepages of staff at an organisation represent people at that >>organisation - that list can be provided by a Web service at any given time, >>or it is possible to determine whether a given resource is in that set, but >>it cannot be enumerated cleanly in a static document. >> >>(EARL statements about resources of this type are an example of a use case in >>accessibility - for example that these have been tested and found to contain >>appropriate structure or be valid before they were published). >> >>I am told by Jeremy Carroll that this problem can be dealt with by Jena and >>modelled using OWL. The issue is why this is not something that a "basic" RDF >>processor should be able to deal with. In the aboutEachprefix case it was >>(theoretically) available in basic processors which did not implement other >>"optional" specifications. >> >>=== >> >>Issue 2 - referring to a particular view of a resource >> >>According to the RDF Concepts document, a statement that >><http://www.example.org/foo#svgView(viewBox(0,200,1000,1000))> <foo:isLike> >><bar:something> >> >>refers to something which is defined in the version of >>http://www.example.org/foo that has an RDF MIME-type. So if there is nothing >>returned with that MIME-type then the statement doesn't have a defined >>subject. >> >>It seems you also can't rely on content negotiation to say something like >> >><http://www.example.org/foo#svgView(viewBox(0,200,1000,1000))> >><foo:viewableAs> <mime:image/svg+xml> . >> >><http://www.example.org/foo#svgView(viewBox(0,200,1000,1000))> >><foo:describedInHTML> <http://www.example.org/foo#someDesc> . >> >>An accessibility use case is describing particular views of documents under >>particular conditions - for example giving some information about what kinds >>of 'delivery context' can make sense of that part of a resource, or pointing >>to another resource which can be used to understand a resource which a person >>with a disability can't use directly. It is often important to talk about a >>part of a document, because some parts will be accesible to people and others >>won't, and they want to know which is which. In the presence of >>content-negotiation, statements will be about fragments of versions other >>than the RDF one. >> >>
Received on Tuesday, 25 March 2003 12:13:32 UTC