Re: Proposal for Schema.org extension mechanism

Here's a practical question:

* schema.org/Course is in development for schema.org Core [1]. For purposes
of discussion, say that it wasn't; that schema:Course is part of an
in-development extension
* schema.org/course already has a defined domain and range (schema:Place)
that is somewhat subjectively disjunctive from schema:Course, for online
courses (e.g. from edX)

How is this resolved with the proposed extension mechanism?
Is there a schema-ext123:course which could have a range of schema:Course?

[1] https://github.com/schemaorg/schemaorg/issues/195




On Wed, Mar 4, 2015 at 1:42 PM, Guha <guha@google.com> wrote:

> Very good point. I should have been more clear.
>
>
> Use of schema.org terms has evolved from only search to many other
> applications, both from schema.org sponsors (e.g., Google Now, Cortana)
> to non-search companies (Rich Pins from Pinterest). These applications tend
> to have narrower domains than search and require more specialized
> vocabularies. Many of these more specialized vocabularies, though more
> specialized, also tend to include many of the general terms found in
> schema.org.
>
> We are simply trying to create a mechanism for the to reuse these terms by
> extending schema.org. Of course, they could do their own thing and rely
> on webmasters figuring out namespaces, which terms from which namespace,
> etc. But experience has shown that webmasters often find that too onerous.
> This is an attempt at a solution for that.
>
> And of course, as always, use of vanilla RDFa is always welcome.
>
> Hope this clarifies.
>
> guha
>
> On Wed, Mar 4, 2015 at 11:35 AM, Mark Baker <distobj@acm.org> wrote:
>
>> Hi Guha, everyone...
>>
>> On Sun, Feb 22, 2015 at 8:24 PM, Guha <guha@google.com> wrote:
>> > For
>> > something to go into the core, it not only has to meet the quality bar,
>> but
>> > also be of general interest to a substantial fraction of the internet
>> > community. This second condition does not hold for reviewed extensions.
>>
>> This is a very interesting statement to me. It's certainly possible
>> that I'm missing the point here, as although I've been interested and
>> supportive of (and written code to support) the schema.org effort,
>> I've only recently joined this list. But it's been my understanding
>> since it was first announced that the value here is basically a
>> (potentially temporary) trade-off of decentralized evolvability for
>> ease/speed of deployment. So the search engines basically say via
>> schema.org, "Here's some general terms that we understand", and
>> publishers down-convert their content from vertical-specific terms to
>> those more general terms.
>>
>> The motivation in the current proposal states, "As schema.org adoption
>> has grown, a number groups with more specialized vocabularies have
>> expressed interest in extending schema.org with their terms". I don't
>> doubt that's true, but as we all know, the driving force that makes
>> the schema.org proposition valuable isn't from "groups", it's the
>> search engines and their support of those general terms. As the terms
>> become more and more specific, of interest to smaller and smaller
>> communities, and therefore of less interest to search engines to
>> support, that value evaporates AFAICT.
>>
>> So I really wonder what the benefit is here. For those communities
>> with vocabularies of a less general nature, why not just publish with
>> vanilla RDFa? What value is there to be hitched to schema.org in the
>> way described in this document?
>>
>> Thanks.
>>
>> Mark.
>>
>
>