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Re: Draft minutes for TAG telcon of 2011-06-16

From: Nathan <nathan@webr3.org>
Date: Sun, 19 Jun 2011 16:17:11 +0100
Message-ID: <4DFE12F7.4050107@webr3.org>
To: Alan Ruttenberg <alanruttenberg@gmail.com>
CC: www-tag@w3.org, "Henry S. Thompson" <ht@inf.ed.ac.uk>, Jeni Tennison <jeni@jenitennison.com>, Manu Sporny <msporny@digitalbazaar.com>
Alan Ruttenberg wrote:
> On Sat, Jun 18, 2011 at 6:44 PM, Nathan <nathan@webr3.org> wrote:
> 
>> Henry S. Thompson wrote:
>>
>>> ISSUE-35 -- Microdata/RDFa relationship
>>>
>> Nice to see this being focussed on.
>>
>> I have some concerns that the major background difference between the
>> approaches, which resulted in two differing specifications, has not been
>> given much focus. From Jeni's document:
>>
>>  * RDFa allows entities to be assigned more than one type; microdata
>> supports a maximum of one type
>>
> 
> Microdata's type hierarchy includes multiple inheritance. So (if) you had
> the power to define a new type, you could have it have the multiple types
> you desire as parents and then use that single type, with the same effective
> result as using multiple types directly.
> 
> It is a bigger deal, IMO, that there is a gatekeeper (schema.org) for
> defining new types.
> 
> The non-monotonicity resulting from schema.org defining as Text many
> properties that will be in the future candidate for being Things is also a
> major difference.

Agree, however with the note that it's focussed on Class based 
inheritance rather than property based (or both together).

Best,

Nathan

> Alan
> 
> 
>> I firmly believe this is the key difference in approaches, microdata is
>> primarily focused on using a classical "class blueprint" style of schema,
>> where each class/type is set in stone, and has a fixed enumerable set of
>> properties. Whereas RDF(a) mixes and matches from multiple vocabularies.
>>
>> Whilst this only results in minor difference in the surface syntax, the
>> mental model, processing model, and how the data is generated / consumed  /
>> interacted with and consumed is very different.
>>
>> My primary concern is that this may need to be addressed first of all,
>> because if the different approaches are both needed, then two different
>> surface syntaxes for the two styles may well be needed, and the possible TF
>> may need to focus on clearly identifying the needs of both approaches to
>> ensure that features from one don't creep in to the other making it
>> unusable. If it isn't addressed, then the differences in background mental /
>> schema models may be enough to make a merged single syntax useless/confusing
>> for one or more parties.
>>
>>
>>    TBL: The Task Force may fail -- but I don't want them to come back and
>>>   say "We succeeded -- no change is necessary"
>>>
>> +1, Can't stress that enough.
>>
>> Best,
>>
>> Nathan
>>
>>
> 
Received on Sunday, 19 June 2011 15:18:22 GMT

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