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Re: Straw Poll (ISSUE-1)

From: Gregg Kellogg <gregg@kellogg-assoc.com>
Date: Fri, 21 Oct 2011 16:18:17 -0400
To: Jeni Tennison <jeni@jenitennison.com>
CC: HTML Data Task Force WG <public-html-data-tf@w3.org>
Message-ID: <50E1531F-0C2B-42B0-A2B3-A79B219B51D9@greggkellogg.net>
With detail below, my choice is 3a along with the registry idea from 2b.

Gregg

On Oct 21, 2011, at 11:40 AM, Jeni Tennison wrote:

> All,
> 
> This is a quick straw poll to gauge feeling in the group about whether/how microdata processors generating RDF should use vocabulary knowledge to generate appropriate/useful RDF. The options are:
> 
> 1. all processors use the same (default) mapping for all vocabularies

This would be my first choice, as providing options to processors is unreliable and will lead to different results, but I don't think it's really possible.

> 2. all processors use a default mapping for unknown vocabularies and a customised mapping for known vocabularies where the known vocabulary mappings are:
>    a. a pre-defined set of popular vocabularies

I'm uncomfortable with a W3C spec choosing winners among "popular" vocabularies; best done in an external registry.

>    b. drawn from a registry

We would define a context in which necessary details of specific vocabularies are defined (such as property URI generation, multi-valued properties as lists and property range and cardinality specifications. Making it machine readable makes it possible for processor maintainers to cook the information into their processors so that it does not need to be derived at runtime. This also means that we need to control and specify update frequency and other rules, as RDFa must for it's default context.

>    c. determined by resolving the vocabulary's schema

Elegant, but unfeasible. Also, it is not always possible for processors to load this information at processing time. Also, I don't think that vocabulary authors typically do this properly, due to the complexity of the OWL specification.

> 3. different processors have different sets of mappings and must specify how they are set
>    a. all processors have the same default mapping for unknown vocabularies

Probably the best realistic choice, along with the registry from 2b. Note that this should allow a processor to provide parameters to override the default

>    b. processors must also specify what default mapping they use

I don't like the idea of processors having different defaults, but they could be called from an environment in which customized default settings are used.

> Please indicate which option(s) you prefer and which you can't live with.
> 
> I'll pull together results on Tuesday morning UK time.
> 
> Cheers,
> 
> Jeni
> -- 
> Jeni Tennison
> http://www.jenitennison.com
> 
> 
Received on Friday, 21 October 2011 20:19:11 GMT

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