[foaf-protocols] First WebID Teleconference minutes (July 27th 2010)

Bruno Harbulot Bruno.Harbulot at manchester.ac.uk
Mon Aug 2 17:51:15 CEST 2010

On 02/08/10 16:21, Henry Story wrote:
> On 2 Aug 2010, at 16:34, Bruno Harbulot wrote:
>> On 02/08/10 12:54, Henry Story wrote:
>>> [...]
>>> In the end what matters is that we can all interoperate, and that we can build cool apps.
>> Sure, but that's an argument in favour of a small number of formats and to have them mandatory (at least on one side).
> It is a very good argument in favor of a few. But it is a practical argument.
> The spec can make this argument, without specifying that it MUST be so.
> As you say in your last email
> "To me, it's quite clear that social networking websites that
> choose to implement WebID but don't serve an HTML representation will
> fail to be considered useful by users, so there will be a bit of
> self-selection there anyway."

It's quite a different thing though. I'm still in favour of a 'MUST' for 
the formats on the verification agent side, because there's no human 
interaction there. Machines need to be told what to do.

While it's quite obvious for the user that a WebID provider and social 
networking site will be rubbish because it doesn't provide something 
nice for the user, it's much less obvious for users to know that they 
can't log on because the verification agent of the service they're 
trying to use doesn't support the mandated/recommended formats.
Self-selection won't work without appropriate user feedback, which may 
be limited depending on how deep the verification agent is.

(Of course, we should also recommend that verification agents provide 
appropriate feedback on the site where they're implemented, but it's 
impractical to expect strict guarantees in that respect.)

>> GRDDL and XSPARQL may be good technologies to help implementing
>> this
conversion, but we shouldn't assume that they're there.
> but we should be open to them be used and allow them to be used. If
> a
group manages to bring us a few millions users because psychologically
they just can't get their mind around RDF, then we should help them do
what they want to do correctly, and welcome those people onboard.
> Of course, if everyone is happy to use rdf/xml and rdfa then we will
all be more efficient. And of course other formats will need to have
good arguments, to convince us all to bother with their special case.

I've never been against using other formats on top of the mandatory 
ones. If people want to support GRDDL, XSPARQL, JSON, why not indeed.
We just need a common denominator between WebID publishers and 
verification agents. As we've discussed earlier, this is easier to 
obtain that by mandating support for all the selected formats (currently 
RDF/XML and HTML+RDFa) on the verification agent and for at least one of 
the selected formats on the publication side.

Sorry to insist, but we're back to something more or less equivalent to 
that wording in this case:

> A Verification Agent MUST be able to process documents in RDF/XML
> A server responding to a WebID Profile request MUST be able to return a
> representation in RDF/XML (using media type application/rdf+xml) or
> XHTML+RDFa (using either media type text/html or media type
> application/xhtml+xml). In addition, either parties may support any
> other RDF format via HTTP content-type negotiation.

Best wishes,


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