[topicmapmail] Are Facets Really Simple After All?

[Murray Altheim]

Thomas B. Passin wrote:
>>>Murray Altheim wrote:
>>
>>But Tom, it's really more than that. It's not just UI stuff, but
>>any meta-information that might be considered about the Topic,
>>but not sharing the subject of the Topic. So, in addition to the
>>UI stuff in my example (of which 'created date' is not really UI),
>>there'd be any of the relevant Dublin Core-style metadata such as
>>creator, contact person, contributor, resource type, identifier,
>>source, rights, medium, version number, etc.
>
> How did we get from looking at representing facets to capturing all 
> possible metadata about a topic?  I do not look at them as the same 
> thing.  Now personally, I would have no problem with creating a topic to 
> or association hold certain meta data if it was all related and coherent 
> and if I cared  to distinguish the collection from other meta data about 
> the topic. That would be similar to using a bnode in RDF.

These are my two basic models, the ones I started the thread with:

   Model A, the RDF-like attachment of properties to Topics.
   Model T, the FC-like attachment of facets to Topics.

Sorry if I've or you've confused them. I'm essentially (at this hour)
advocating both "hasProperty" and "hasFacet" PSIs, for Models A and T,
resp.

> This does not mean that I advocate overwhelming my topic maps with lots 
> and lots of collection topics, but sometimes they may be useful.
> 
> Anyway, there is a fine line between data and meta data.  Some would say 
> it is so fine as to be non-existent.  I think a more interesting 
> distinction is between (meta) data that is about a single subject (like 
> author, date of publication, etc.), and data that inherently involves 
> two subjects, such as annotations one may make about published works. 
> Annotations arise from an interaction between the work and the person, 
> and thereby are - in my mind, at least - inherently different from data 
> that "belongs" to a particular topic.  Associations vs occurrences, perhaps?

Well, this is why I think having a discussion like this is valuable,
and perhaps being able to create some language that distinguishes
some rough boundaries between "facets" and "properties". Obviously,
each application will have to interpret what is the best way of
modeling its concepts and relations. I am not trying to advocate
universal rules for ontologies (far from it -- I don't believe in
them).

>>If you generalize from a "UI proxy" to simply a "proxy", you're
>>basically suggesting a container for any kind of Topic metadata
>>that is connected to but not contained within the Topic. If for
>>each Topic we wanted to store ten kinds of metadata, 
> 
> But Murray, in the past you have said you would be delighted to make 
> large numbers of "properties" into topics so they could become the 
> targets of any number of associations.  So why do you suddenly have a 
> problem with these containers? 

I'm happy to advocate either, if it's appropriate to the circumstance.
I was really pushing for reifying facets as Topics because I think
they need to participate (generally) in their own hierarchies and
relations, whereas (generally) properties don't "deserve" such high
priority treatment, so I'm scurrying around in the dust for a decent
solution for them. I'm happy with my current ideas for facets.

> Anyway, whether to use containers like 
> this will depend entirely on the data you want to model, how you wish to 
> think about it, and possibly what you want to do with it as well.  I am 
> not avocating them for all meta data or all facets. I simply responded 
> to your well-grounded statement that certain UI properties were "not 
> right" for the topic itself.  Presumably there would be many other 
> properties that are "right", and the proxy topic would not make sense 
> for them.

I should have read ahead to what you'd concluded with -- we are again
in agreement.

Murray

......................................................................
Murray Altheim                    http://kmi.open.ac.uk/people/murray/
Knowledge Media Institute
The Open University, Milton Keynes, Bucks, MK7 6AA, UK               .

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