Hiya,

Karen Coyle <[log in to unmask]> wrote:
> I wonder how easy it will be to
> manage a metadata scheme that has cherry-picked from existing ones, so
> something like:
>
> dc:title
> bibo:chapter
> foaf:depiction

Yes, you're right in pointing out this as a problem. And my answer is;
it's complicated. My previous "rant" on this list was about data
models*, and dangnabbit if this isn't related as well.

What your example is doing is pointing out a new model based on bits
of other models. This works fine, for the most part, when the concepts
are simple; simple to understand, simple to extend. Often you'll find
that what used to be unclear has grown clear over time (as more and
more have used FOAF, you'll find some things are more used and better
understood, while other parts of it fade into 'we don't really use
that anymore')

But when things get complicated, it *can* render your model unusable.
Mixed data models can be good, but can also lead directly to meta data
hell. For example ;

  dc:title
  foaf:title

Ouch. Although not a biggie, I see this kind of discrepancy all the
time, so the argument against mixed models is of course that the power
of definition lies with you rather than some third-party that might
change their mind (albeit rare) or have similar terms that differ
(more often).

I personally would say that the library world should define RDA as you
need it to be, and worry less about reuse at this stage unless you
know for sure that the external models do bibliographic meta data
well.

HOWEVER!

When we're done talking about ontologies and vocabularies, we need to
talk about identifiers, and there I would swing the other way and let
reuse govern, because it is when you reuse an identifier you start
thinking about what that identifiers means to *both* parties. Or, put
differently ;

It's remarkably easier to get this right if the identifier is a
number, rather than some word. And for that reason I'd say reuse
identifiers (subject proxies) as they are easier to get right and
bring a lot of benefits, but not ontologies (model proxies) as they
can be very difficult to get right and don't necessarily give you what
you want.

Just my .2 AUD.


Alex

* https://plus.google.com/u/0/111886865967199209050/posts/QLx3LLeseeD

-- 
 Project Wrangler, SOA, Information Alchemist, UX, RESTafarian, Topic Maps
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