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Re: Dropping RDF mapping from microdata spec

From: Jeni Tennison <jeni@jenitennison.com>
Date: Wed, 27 Jul 2011 22:25:04 +0100
Cc: Richard Cyganiak <richard.cyganiak@deri.org>, "www-tag@w3.org List" <www-tag@w3.org>
Message-Id: <966E6A70-D9DB-47F1-8F2A-CEC40EB2AADB@jenitennison.com>
To: Michael Hausenblas <michael.hausenblas@deri.org>

On 27 Jul 2011, at 18:59, Michael Hausenblas wrote:
>> I had a recollection that you were also creating RDF versions of pages that contained schema.org microdata. Is that right?
> Hmmm, I'm a bit unsure if you're referring to the examples/ section of Schema.RDFS.org [1] or to the gateway [2] which is based on Ed Summers' rdflib parser plug-in for microdata [3] or, maybe, to the set of scraper scripts [4] we use to generate all kinds of structured data (RDF, CSV, JSON) from the Schema.org HTML pages?

I was meaning the gateway.

>> My question is, if I have recalled correctly that you are dynamically creating RDF from pages marked up with schema.org microdata, is the mapping that you use generic (e.g. map any short-name property into a URI based on the itemtype of the nearest item) or specific to schema.org (i.e. recognise those particular short-name properties on items with a schema.org type)?
> IIRC, we have a Schema.org-specific mapping in place, but I feel Richard is more competent to answer this one - Richard?
> Related (because of organisational proximity) is the any23 issue 173 [5] - note that any23 is used in Sindice and has hence also some potential effect on the ecosystem.
> HTH ... ?

Yes, thanks :)

From what I can see, the documented meaning of http://schema.org/startDate and http://schema.org/endDate is different depending on whether the item is a TVSeason/TVSeries or an Event. IIRC, one reason that Hixie gives for the complexity of the generated property URIs in the current microdata/RDF mapping is to ensure that properties with potentially different semantics (that appear on items of different types) have distinct URIs. But of course when you have inheritance in a vocabulary like schema.org, you don't want distinct URIs by type.

Makes me think you can't have a generic mapping that gives a good output in RDF terms.


Jeni Tennison
Received on Wednesday, 27 July 2011 21:25:28 UTC

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