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Fwd: [research-all] Fwd: Multiple types from different vocabularies (ACTION-7)

From: Martin Hepp <martin.hepp@ebusiness-unibw.org>
Date: Tue, 18 Oct 2011 22:58:54 +0200
To: public-html-data-tf@w3.org, Gregg Kellogg <greggkellogg@gmail.com>
Message-Id: <C9B5FF00-48C1-473F-8D5F-9BC16BE25C76@ebusiness-unibw.org>
Hi all:

When thinking about about Hixie's requirements on Microdata vocabularies, I come to the conclusion that what we need for an efficient bridge from RDF/OWL vocabularies to the Microdata world is a way to express these facts about a Microdata vocabulary so that a parser can configure the Microdata2RDF conversion according to that meta-data. 

We could e.g. define a new W3C vocabulary for that or to add respective annotation properties to the OWL namespace.


> Begin forwarded message:
>> From: Jeni Tennison <jeni@jenitennison.com>
>> Date: October 15, 2011 9:57:36 PM GMT+02:00
>> To: Martin Hepp <martin.hepp@ebusiness-unibw.org>
>> Cc: public-html-data-tf@w3.org
>> Subject: Re: Multiple types from different vocabularies (ACTION-7)
>> In recent mails, Hixie said [1]:
>>> Incidentally, note that you can't just take, say, an RDF vocabulary, or a Microformats vocabulary, and just use it in microdata directly. A microdata vocabulary has to define processing rules that are often not provided for RDF and Microformats vocabularies, and has to use the terms defined in the HTML specification to describe how the terms work. You can see examples of how to define vocabularies in the HTML standard:
>>> http://www.whatwg.org/specs/web-apps/current-work/multipage/microdata.html#mdvocabs
>> and defined a microdata vocabulary as [2]:
>>> A vocabulary is a set of property names, the semantics of those property 
>>> names, the processing rules for properties that use those names, the error 
>>> handling for items that use these properties incorrectly, the meaning of 
>>> the itemid="" value in the context of this vocabulary, potentially the 
>>> "sub"vocabularies of other untyped items that are the values of properties 
>>> whose names are defined by the vocabulary, and the set of one or more 
>>> types that identify that vocabulary.
>> I've put these quotes as placeholders on the wiki page about vocabulary design [3] but we need to flesh that page out more. Going through the microdata spec [4] there are things like:
>> * whether the types can be dereferenced
>> * for each type, whether itemids are allowed and how they are interpreted
>> * how items with the same itemid are handled
>> * which properties are allowed on which types
>> * how many and what values are allowed for each property
>> The first three are easy to answer for RDF-friendly vocabularies, I think. The spec doesn't mention anything about having to specify error handling behaviour for property values, but that should be added to the list if we're creating guidelines.
>> You know it would be really great to use GoodRelations as an example of an RDF vocabulary being adapted so that it can also be used with microdata, showing the steps that need to be taken by vocabulary authors to port existing RDF schemas. Could I persuade you to put together a description of what you've had to do on the wiki page at [3]? (We might perhaps extend that to show use with microformats-2 if we were feeling ambitious.)
>> Thanks,
>> Jeni
>> [1] http://lists.w3.org/Archives/Public/public-html-data-tf/2011Oct/0085.html
>> [2] http://lists.w3.org/Archives/Public/public-html-data-tf/2011Oct/0100.html
>> [3] http://www.w3.org/wiki/HTML_Data_Vocabularies
>> [4] http://dev.w3.org/html5/md/Overview.html
>> -- 
>> Jeni Tennison
>> http://www.jenitennison.com
Received on Tuesday, 18 October 2011 20:59:22 UTC

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