[sc34wg3] Occurrences in the data model

Murray Altheim sc34wg3@isotopicmaps.org
Wed, 07 Jan 2004 12:53:01 +0000

Martin Bryan wrote:
>>Would/Could it be useful to know whether the concept - however formulated -
> of scope helps here: can we state that we are interested in "documents with
> version numbers between 1 and 3"; or "items in the night sky between RA/DEC
> coordinates xy and x'y' " ? It seems that all the debate about facets/scope
> has looked (correctly) at the issue of an "axis" of interest, but not this
> problem of discrete and indiscrete values/ranges.
> Actually this was thought about in some lengths in 13250. Because we were
> using HyTime we could define discrete axes ofany granularity and even link
> axes of different granularities. The pointers used for facet values could
> then point to positions on axes.


The model that I've been implementing includes the ability to use
not only strings but datatyped measurements, and I'm currently
working up a Topic Map for a set of PSIs for measurement units
so that I can add units as well. I wasn't going down the HyTime
path of considering these as axes, but I have been playing with
both ordering predicates and with the idea of timelines, which
are of course single dimension axes. So maybe there's a simpler
solution than HyTime that still has usefullness. I must admit
I had a conversation with Eliot about HyTime once that blew my
mind over the possibilities, but I think many folks might have
the "blew my mind" experience in the negative sense over such a
complicated system.


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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