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Issue chas-01 aboutEachPrefix

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Tue, 25 Mar 2003 17:13:43 +0000
Message-Id: <5.1.0.14.0.20030325171309.2bb6b928@0-mail-1.hpl.hp.com>
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 Fundaci˛n 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 GMT

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