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Re: Some interesting things that show up when using a reasoner to classify schema.org

From: Simon Spero <sesuncedu@gmail.com>
Date: Thu, 22 Jan 2015 14:15:21 -0500
Message-ID: <CADE8KM4VG1wBZunqCK6n3iPFRYU9D9imJt8N3zjLDBvB+qMHeg@mail.gmail.com>
To: Gregg Kellogg <gregg@greggkellogg.net>
Cc: ☮ elf Pavlik ☮ <perpetual-tripper@wwelves.org>, W3C Web Schemas Task Force <public-vocabs@w3.org>, Martin Hepp <martin.hepp@unibw.de>
On Jan 22, 2015 1:31 PM, "Gregg Kellogg" <gregg@greggkellogg.net> wrote:
>
> The difference between using the unionOf and domainIncludes variation is
that domainIncludes is open, and allows other vocabularies to extend the
domain for their purpose (as, for example, yoursports.com does). Whereas,
unionOf uses an rdf:List, which can't be extended. Other than the
extensibility issues, then domain/rangeIncludes are essentially the same as
unionOf.

That is one of at least two possible interpretations;

(1) domainIncludes statements are simply documentation, so that all domains
are :Thing, and all ranges are ( :Thing or :DataType ) ; OR

(2) domainIncludes for a given time interval form a closed union.

When the bicycling guitarist was flagged by the Google rich snippet testing
tool for using the genre property on MusicGroup, after a domainIncludes had
been added to the schema, but before the tool had been modified, it
strongly suggests that the interpretation adopted by Google is (2).

Note that if the domain of a property is specified to be a  ( possibly
union) class, but ought be applicable to some thing that cannot an instance
of that class, then there is an error- either in the definition of the
property, the class, or in the specification of its domain.

Note that subclassing is still applicable.

Simon
Received on Thursday, 22 January 2015 19:15:53 UTC

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