[sc34wg3] SAM 3.4.4 Reification and 3.4.5 Properties

Lars Marius Garshol sc34wg3@isotopicmaps.org
16 Apr 2003 23:16:16 +0200

* Luis J. Martinez
| I think you are using the word reification as a computing facility
| to make a Topic Map item, like an Association, be view as a Topic
| subject under the SAM framework. 

I am. That's the way "reification" is used in artificial intelligence
and logic. I took my definition from "Artificial Intelligence - A
Modern Approach", by Russell & Norvig. It's also the way the term is
used in RDF.

| A modeling construct. Well, it just happens that what you are
| modeling, Topic Maps, does that exact thing. Topics are a facility
| to make information objects expressed as subjects under the Topic
| Maps framework.

Yes, but there's a difference between information objects that are
part of the topic map and those that are not. If you didn't have
reification you wouldn't be able to speak about anything that was part
of the topic map; you would only be able to speak about what was
outside the topic map.
| I think what is confusing is that for the past few years we have
| been talking about reifying subjects with topics. 

Yes. That was not a good use of the term. It made it hard to
understand the relationship between topics and subjects (topics
represent subjects, end of story) and it also left us without a term
for reification (which even so did not stop us from using it to mean
reification in particular rather than representation in general).

| Now, we want to stop using that word because the SAM needs to reify
| things as a modeling function. 

No. We want to clean up the use of the term. This has nothing to do
with the SAM, it's just that rewriting the standard (as SAM++) gave us
a chance to fix this terminology bug, so that's why the change
happened now. Norway would have submitted NB comments to this effect
against ISO 13250:2000 long ago if we hadn't known that the whole
thing would be replaced anyway.

| I think I understand this, but there is some kind of
| self-referencing thing going on that is making my head spin.

Reification will do that to you. :-)

Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >