Re: GRDDL and OWL/XML

Jeremy Carroll wrote:
>
> To record my opinion on these points, which you agreed differed ...
>
[snip]
>
>> So:
>>
>>    1) It seems general opinion in the GRDDL WG that having a GRDDL 
>> Transformation Property point to a non-executable list of 
>> implementations is not a useful use of GRDDL, and the GRDDL WG did 
>> not explicitly discuss this possibility when creating the GRDDL 
>> Specification or test-cases. A GRDDL transformation, while not 
>> necessarily XSLT, is usually executable, and currently all examples 
>> are in XSLT.
>>
>
> -1 I liked Bijan's plug-in architecture immensely.
I liked Bijan's idea of the "plug-in" architecture as well, but alas - 
the details are quite fuzzy. Right now pointing to a list would not be 
executable and not even allow the choice by current GRDDL clients of 
choosing a transform.  And I think it's already specified in the "local 
policy" part of GRDDL - if an agent already has a preferred "local" 
GRDDL transform, it is of course free to use that rather than following 
its namespace.

I think the central question is whether or not at this point the GRDDL 
WG recommends that at least one GRDDL transform point to either:

1) A non-executable list of implementations
2) An executable transform, likely an XSLT one.

One could of course have *two* GRDDL transforms, one that points to 1) 
and one that points to 2), but we are not sure how 1) would behave with 
current GRDDL transforms.

I think almost everyone except Bijan and possibly Jeremy agreed that at 
the current moment, 2) would be more useful than 1).  A third option, a 
"plug-in" architecture,  is an interesting and good idea, but one that 
could be left to local policy for the current time as currently it is 
unimplemented and unspecified.
>>    2) However, while the "cost" of alienating developers of other 
>> non-GRDDL transformations may exist, this is a misunderstanding about 
>> the "normative" nature of GRDDL transformations. In particular, a 
>> list of other conformant implementations could be accessible at the 
>> namespace document. Also, a few sentences explaining GRDDL and the 
>> fact that it is no more "normative" than other implementations could 
>> be included in the namespace document. If this does actually cause 
>> problems, these problems could be dealt with re the usual feedback 
>> channels of the W3C. The advantage of having a GRDDL from OWL 2 to 
>> RDF is that it is to a larger audience (RDF users without an explicit 
>> OWL 2 to RDF transform), who might otherwise be unable to have what 
>> benefits OWL 2. in RDF, can have these benefits with a minimal of work.
>
> +1
>
>>
>>    3) Re the possibility of the OWL namespace document being 
>> overloaded by requests for the transform, we do in the specification 
>> encourage caching of GRDDL transformations. Regards the possibility 
>> of GRDDL transformations being "automatically" run, this is a matter 
>> of local policy. Current libraries such as Redland and Jena do allow 
>> GRDDL to be turned on explicitly by the local client.
>
> +1
>
>>
>>    Although this is not the solution that Bijan wants per se, think 
>> this is the general opinion of the GRDDL WG members who have 
>> responded so far on this list, except for possibly Jeremy Carroll. 
>
> I only disagree on that point. I would be quite happy with a grddl 
> transform specified in prose, in addition to one in XSLT.
>
> I hope (but don't know) that the Jena implementation would quietly 
> ignore it. If it didn't that would be a bug. (Although I am not sure 
> what the support status of that component of Jena will be in the future).
>
>> Thanks for the provocative and intelligent critiques and comments re 
>> GRDDL and OWL 2.
>>
>>    The choice of whether or not to include a GRDDL transformation 
>> that is an XSLT from OWL2 XML to RDF is, of course, in the competent 
>> hands of the OWL 2 WG. However, I do hope this feedback helps clarify 
>> things.
>>
>
> +1
>
>
> If there is any other WG member who supports my -1 I would suggest 
> that that part of the message be struck before sending to the OWL WG
> (OTOH David might strongly disagree with me, and HP would abstain, at 
> least for another two weeks :) )
>
> Jeremy
>
>

Received on Friday, 16 May 2008 16:52:59 UTC