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Re: Telecon Agenda - November 10th 2011, 1400 UTC

From: Ivan Herman <ivan@w3.org>
Date: Thu, 10 Nov 2011 14:08:39 +0100
Cc: Manu Sporny <msporny@digitalbazaar.com>, RDFa WG <public-rdfa-wg@w3.org>
Message-Id: <CF3F2812-C03A-4B43-8D27-6BAB95090166@w3.org>
To: Toby Inkster <tai@g5n.co.uk>
Regardless of the fate of this proposal... I do have a general view of the microdata/rdfa issue, ie, when would you use one or the other.

For simple things, if one wants to stay on the level of schema.org, there is indeed not much difference. As long as this is the only thing you want to do. However, at least in my view, the selling point of RDFa is that it can be used for more. If somebody wants to connect to other vocabularies, he/she can use a much more flexible way of accessing resources (via prefixes, vocabs, etc); it is much easier and much more natural to assign several types to the same resource; one can add datatypes; and there are some constructions that are possible in RDFa 1.1 full that make it easier to express than in microdata. Ie, RDFa is an extension point, microdata is not.

It is true that RDFa Lite + the current proposal makes it very close to microdata. Let us put it this way: it makes as easy for authors as microdata. But it leaves the door open to do more, which microdata never will.

Ivan

On Nov 10, 2011, at 12:53 , Toby Inkster wrote:

> On Wed, 09 Nov 2011 11:20:43 -0500
> Manu Sporny <msporny@digitalbazaar.com> wrote:
> 
>> 2. @property proposal
>>    http://www.w3.org/2010/02/rdfa/wiki/PropertyAndTypeof
>> 3. @typeof proposal
>>    http://www.w3.org/2010/02/rdfa/wiki/PropertyAndTypeof
> 
> I'm not sure whether or not I'll be able to attend, but shall try. In
> the mean time, here are my thoughts on the proposed changes.
> 
> Executive summary: -1.
> 
> Details: There are several reasons I object to these changes. Firstly,
> and I think most importantly, they create too much magic. They make the
> behaviour of @property dependent on whether @href/@src/@resource are
> present on the same element, and in some case dependent on whether
> @typeof is present too.
> 
> RDFa already has some magic - such as the absence of @rel/@rev allowing
> @resource/@href (and now @src) to set a subject for triples. Personally
> I think we should be aiming to *reduce* the amount of magic in RDFa,
> not increase it.
> 
> Secondly, this breaks backwards compatibility with RDFa for a perceived
> benefit that I think is imaginary. The idea appears to be to make RDFa
> closer in syntax to Microdata because Microdata is (supposedly!)
> simpler. But even if we make RDFa as (supposedly) simple as Microdata,
> I don't see how that does RDFa any favours - it still doesn't provide a
> compelling reason to use RDFa over Microdata. And I don't see how it
> does Web authors any favours having two, almost identical, but still
> subtly different syntaxes for achieving the same thing.
> 
> Even if we succeeded in making RDFa syntactically similar to Microdata,
> what then? What's our selling point? Why should people use RDFa? Aren't
> Microdata users going to say, "OK, so RDFa is similar to Microdata
> now... so I'll just keep using Microdata then. Because at least it
> doesn't have a track record of breaking backwards compatibility with
> every minor revision."
> 
> So to summarise, I think these changes would make RDFa more
> complicated, not simpler; I think the ultimate aim of these changes (to
> make RDFa more popular) would not be achieved by them, and Web users
> would not benefit from the changes; and I think breaking backwards
> compatibility in such a fundamental way would actually be detrimental
> to RDFa's adoption.
> 
> -- 
> Toby A Inkster
> <mailto:mail@tobyinkster.co.uk>
> <http://tobyinkster.co.uk>
> 
> 


----
Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Thursday, 10 November 2011 13:06:40 GMT

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