Re: Another example of Wikidata + schema.org for type enumerations

On Sat, Feb 22, 2014 at 4:37 PM, Gregg Kellogg <gregg@greggkellogg.net>wrote:

> On Feb 21, 2014, at 7:11 PM, Dan Brickley <danbri@google.com> wrote:
>
> > Here's another example along the lines I sketched recently, after
> > sitting down with Denny today and looking at Wikidata. It is an
> > attempt to show how "types" handled externally from schema.org could
> > be written (in this case in RDFa) alongside basic schema.org types. We
> > revisit the use case of having more kinds of "place of workship" than
> > are anticipated in the schema.org core.
> >
> > A couple of things to note about Wikidata first:
> >
> > 1. it does have basic properties for 'instance of' and 'subclass' but
> > there is no formal or software-backed understanding of these. Most of
> > Wikidata views these as simply more data about an entity. The Wikidata
> > software does not really have a notion of entities having types, this
> > is something added at a later level as data. Perhaps if type-like
> > constructs become common and popular in the community some UI or API
> > support might emerge (by very rough analogy, think about hashtags and
> > retweets in Twitter, which initially were also "just in the data").
> > I'll try to write type-like-entity instead of 'type' when talking
> > about Wikidata.
> >
> > 2. although the factual data in Wikidata is currently often fairly
> > thin, there are already many mappings to other identifiers, e.g. 1-2
> > million have Freebase links, which in turns brings in more factual
> > background data.
> >
> > So here's an example, we describe the entity
> > https://www.wikidata.org/entity/Q2046262 (Pagoda Songyue) as falling
> > into the wikidata type-like-entity
> > https://www.wikidata.org/entity/Q199451 (Pagoda), and then anchor that
> > in the schema.org 'PlaceOfWorship' type.
> >
> > <div vocab="http://schema.org/" typeof="PlaceOfWorship
> > https://www.wikidata.org/entity/Q199451">
> >  <span property="name">Pagoda Songyue</span>
> >   <span property="description">One of the few intact sixth-century
> > pagodas in China, located at the Songyue Monastery on Mount
> > Song.</span>
> >  <link property="url" href="https://www.wikidata.org/entity/Q2046262" />
> >  <link property="sameAs" href="
> https://en.wikipedia.org/wiki/Songyue_Pagoda" />
> >  <link property="sameAs" href="http://www.freebase.com/m/03bz2xf" />
> >  <div itemprop="geo" itemscope itemtype="
> http://schema.org/GeoCoordinates">
> >      <meta itemprop="latitude" content="34.501611" />
> >      <meta itemprop="longitude" content="113.015917" />
> >   </div>
> > </div>
>
> How does <http://www.freebase.com/m/03bz2xf> bring in machine-readable
> factual information? It doesn't seem to have any markup. Although, <
> http://rdf.freebase.com/m/03bz2xf> ultimately does return some Turtle,
> but the content type is text/plain, so it's not too friendly to my
> distiller. Some content-negotiation across these would be useful and/or
> marking up the Freebase HTML using RDFa or microdata.
>

There used to be content negotiation at
http://rdf.freebase.com/ns/m/03bz2xf but
it looks like it's broken currently.  It would redirect to either the HTML
page or to http://rdf.freebase.com/rdf/m/03bz2xf.  This might have gotten
broken as part of moving the APIs to Google's infrastructure.


>  Perhaps Freebase could also declare an equivalent to the Wikidata page,
> they do both say they're equivalent to the same Wikipedia pages in this
> case, anyway. (Denny?)
>

Dan mentioned this but without a specific link.  There are 2M
Freebase<->Wikiedata links published here
https://developers.google.com/freebase/data#freebase-wikidata-mappings  As
you pointed out, it's also trivial to link them transitively through their
joint Wikipedia links.


> > In
> http://blog.schema.org/2012/05/schemaorg-markup-for-external-lists.html
> > a while back from schema.org, we wrote about the importance of
> > 'external enumerations'. Wikidata barely existed back then. Now that
> > Wikidata is real, I'd like to encourage people to take a look. The
> > potential for combining Wikidata and schema.org is well worth some
> > thought...
>
> +1, this is a vendor neutral namespace that the community can directly
> affect. Therefore, it is inherently more manageable and stable than either
> Freebase or DBpedia.
>

Wikidata is vendor neutral and more politically acceptable in many circles,
but I'm having a hard time see how it's more manageable and stable.  It's
biggest weakness right now is coverage but this will hopefully improve
rapidly.

Tom