[sc34wg3] Use cases for occurrence variants

[Nikita Ogievetsky]

Steve Pepper wrote:

> At 20:16 04.03.2003 -0800, Nikita Ogievetsky wrote:
> >To get occurrence variants discussion down to Earth
> >I suggest that we try to summarize use cases.
> >
> >Here are those that I know of or have seen mentioned so far:
> >
> >1. Thumbnail(s) of an image.
> >2. Description of an image (displayability).
> >3. Alt text (displayability).
> >4. Sorting occurrences (sortability).
> >5. Alternate address depending on device context, protocol, etc.
> >6. Model inconsistency between base names and occurrences.
> >
> >Any others?
>
> I think that pretty much covers it.
>
> #5. is perhaps the most important, so I would put it at the top and
> call it "Alternate renditions" rather than "Alternate address". It
> would include alternate notations, resolutions, sizes, etc. For
> example, in the XML Papers application, the PDF and HTML versions of
> a paper might be variant occurrences of the XML version.

Yep. I was also thinking here of FTP; HTTP; FILE etc. access protocols,
Intranet/ Internet, etc. - depending on context.

> As someone who has been playing devil's advocate and didn't really
> want variant occurrences, your list scares me. What it tells me is
> that there is a whole range of very useful and necessary functionality
> we are excluded from using unless we are prepared to use associations
> instead of occurrences. (And even then we don't have an application-
> independent way of capturing the relationship between variant forms
> of a resource.)
>
> I would almost go as far as to say that without variants, occurrences
> are virtually useless. It surprises me that more people haven't thrown
> up their hands in despair. Maybe no-one is actually using topic maps?
>

I am not sure that I want to go that far... :-)
But I agree that there is a very real requirement that we should seriously
consider.

--Nikita.

Nikita Ogievetsky, nogievet@cogx.com;
Cogitech Inc.        http://www.cogx.com
Topic Maps Tutorials and Consulting.
phone:  1 (917) 406 - 8734