[sc34wg3] Occurrences in the data model
Peter Brown
sc34wg3@isotopicmaps.org
Mon, 22 Dec 2003 23:08:38 +0100
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----- Original Message -----=20
From: Patrick Durusau=20
To: sc34wg3=20
Sent: Monday, December 22, 2003 1:20 PM
Subject: [sc34wg3] Occurrences in the data model
<snip/>
The more interesting case arises with location information,
such as Right Ascension/Declination in astronomy, longitude and
latitude in GIS systems (and targeting systems), where finding all the
occurrences that share a point on a particular axis could well be =
important.
Note that I don't think making coordinates topics would solve the
problem as given the fine grained nature of coordinate systems there
would be a proliferation of topics for any relatively sophisticated
system of coordinates. Not to mention that coordinates are commonly
thought to be characteristics of objects/locations and not subjects in
their own right.
Is there some conceptual reason for this treatment of occurrences in
the data model?
<PB>
On the contrary, I think there is a compelling argument that such =
treatment should be explicitly excluded: they are indiscrete (or =
analogue) variables and can never be defined with a discrete value: in =
taxonomy work, it the phenomenon of spectrum values: as you say, it =
depends on the granularity to which you are prepared to take a =
particular classification.
There is also a principle of economy to be considered: in a vary random =
or unevenly distributed set of values, the "discrimination" offered may =
vary wildly: whereas for one part of the spectrum, values of 21,22, 23 =
might be enough to discriminate between different occurrences; at =
another part you might need values as fine as 1.113, 1.114, 1.115, etc.
You can never know in advance how to model indiscrete values in a =
discrete manner...and it indeed makes assertions about equivalence well =
nigh impossible; do two people with ages of "23", "23 years and 1 day", =
and "22 years 11months and 27 days" all have the same age?
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.
All the best...
Peter
</PB>
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<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV style=3D"FONT: 10pt arial">----- Original Message -----=20
<DIV style=3D"BACKGROUND: #e4e4e4; font-color: black"><B>From:</B> <A=20
title=3DPatrick.Durusau@sbl-site.org=20
href=3D"mailto:Patrick.Durusau@sbl-site.org">Patrick Durusau</A> </DIV>
<DIV><B>To:</B> <A title=3Dsc34wg3@isotopicmaps.org=20
href=3D"mailto:sc34wg3@isotopicmaps.org">sc34wg3</A> </DIV>
<DIV><B>Sent:</B> Monday, December 22, 2003 1:20 PM</DIV>
<DIV><B>Subject:</B> [sc34wg3] Occurrences in the data model</DIV></DIV>
<DIV><FONT face=3DArial size=3D2><snip/></FONT><BR></DIV>
<DIV>The more interesting case arises with location information,<BR>such =
as=20
Right Ascension/Declination in astronomy, longitude and<BR>latitude in =
GIS=20
systems (and targeting systems), where finding all the<BR>occurrences =
that share=20
a point on a particular axis could well be important.<BR><BR>Note that I =
don't=20
think making coordinates topics would solve the<BR>problem as given the =
fine=20
grained nature of coordinate systems there<BR>would be a proliferation =
of topics=20
for any relatively sophisticated<BR>system of coordinates. Not to =
mention that=20
coordinates are commonly<BR>thought to be characteristics of =
objects/locations=20
and not subjects in<BR>their own right.<BR><BR>Is there some conceptual =
reason=20
for this treatment of occurrences in<BR>the data model?<BR></DIV>
<DIV><FONT face=3DArial size=3D2><PB></FONT></DIV>
<DIV><FONT face=3DArial size=3D2>On the contrary, I think there is a =
compelling=20
argument that such treatment should be explicitly excluded: they are =
indiscrete=20
(or analogue) variables and can never be defined with a discrete value: =
in=20
taxonomy work, it the phenomenon of spectrum values: as you say, it =
depends on=20
the granularity to which you are prepared to take a particular=20
classification.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>There is also a principle of economy to =
be=20
considered: in a vary random or unevenly distributed set of values, the=20
"discrimination" offered may vary wildly: whereas for one part of the =
spectrum,=20
values of 21,22, 23 might be enough to discriminate between different=20
occurrences; at another part you might need values as fine as 1.113, =
1.114,=20
1.115, etc.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>You can never know in advance how to =
model=20
indiscrete values in a discrete manner...and it indeed makes assertions =
about=20
equivalence well nigh impossible; do two people with ages of "23", "23 =
years and=20
1 day", and "22 years 11months and 27 days" all have the same=20
age?</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Would/Could it be useful to know =
whether the=20
concept - however formulated - of scope helps here: can we state that we =
are=20
interested in "documents with version numbers between 1 and 3"; or =
"items=20
in the night sky between RA/DEC coordinates xy and x'y' " ? It seems =
that all=20
the debate about facets/scope has looked (correctly) at the issue of an =
"axis"=20
of interest, but not this problem of discrete and indiscrete=20
values/ranges.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>All the best...</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Peter</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></PB></FONT></DIV>
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