Xesam meta-meta-data spec needs attention.

[Mikkel Kamstrup Erlandsen]

2007/5/12, Evgeny Egorochkin <phreedom.stdin at gmail.com>:
>
> On Saturday 12 May 2007 18:02:08 Mikkel Kamstrup Erlandsen wrote:
> > > While
> > > > this could be done, the machine readable ontology does have quite a
> few
> > > > benefits. Fx:
> > > >
> > > >  * You could update the ontology without updating any applications
> or
> > >
> > > search
> > >
> > > > engine code
> > > >
> > > >  * 3rd parties could extend the ontology by installing their own
> ones
> > >
> > > Yes, you could update or extend the ontology, but the new fields won't
> be
> > > automatically populated until the engine is told how to get those from
> > > the original data.
> > > Does this make sense ?
> >
> > Yes you are entirely right. There are still many reasons to allow for
> > extensibility though.
> >
> > It might be that some search engines will extract more rich data than
> the
> > xesam spec. With easily introspectable fields applications can pick this
> up
> > on the fly.
> >
> > It has also been discussed several times how to use common metadata
> > extractors. If applications could install a special-purpose extractor
> then
> > we also need a way to define new fields...
>
> The idea is that applications will use Xesam API to introspect fields, so
> to
> them it doesn't matter where field definitions come from, which format
> etc.
> And the question is maybe we should use API to define these fields instead
> of
> text-files?


Well, the current ssearch API contains no way to introspect the availble
fields (or set them). This could be part of a metadata API, which is yet to
be discussed. Under any circumstance I think that it is valuable to be able
to parse and update the ontology without a running service...

like
>
> xesam::field f("music:composer");
> f.addParent("content:author");


Would this be a dbus service or just a library? I don't think it is a good
idea to hide the actual implementation behind a library. In my eyes the
Right Way (TM) is to standardize the way to create xesam ontologies and then
provide a helper lib to do it (if it is necessary at all).


> So each meta-data extractor defines their specific fields via API + xesam
> core
> defines a set of pre-defined fields to enforce the standard.


Yes, I think that xesam should provide a ready-to-ship ontology. How to
install new ontologies is another matter, how to install new extractors is
yet another matter that has only been discussed lightly without much
consensus...

Cheers,
Mikkel
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freedesktop.org/archives/xdg/attachments/20070512/c151cdb3/attachment.html