[topicmapmail] what I mean by "context" and "bottom-up"

[Martin Bryan]

> 1. A community of contributors has to manage a context : define its
> ontology, scope, subjects, topics, names, associations, types, etc ... and
> build the occurences data base.

Not necessarily "A community" - its often a set of communities, as the current ebXML work for electronic business semantics illustrates clearly.

> I precise what I mean here by "context " : a field of knowledge, or
> interest, or activity, or experience (whatever) pragmatically bound by the
> community of people sharing it and speaking a common language, meaning by
> that the semantics are non-ambiguous in the community. 

I have a different view of context. To me it is the way of identifying which subunits of the set of communities that built the onotology use the topic for which processes. Most communities use a topic for more than one process, but to understand accurately what they mean you have to understand what process they are associating the term with at each of its occurrences.

>That's of course an
> idealistic viewpoint, since in detail, semantics are different for each of
> us, as Jack pointed out. But if you don't split hairs, this definition is
> an operational one. Anyway I insist on this point : a context is "embodied"
> in a community. And it's up to this community to build and clarify its
> ontology. It's an interesting social work in itself.
> That's what I meant earlier in my answer to Martin (or maybe Jim ?) to be a
> bottom-up approach :
> the community and its ontology, whatever its size, is the "local" or
> "ground" or "bottom" level, and if we have to build more general
> ontologies, we'll have to merge them somehow. It has nothing to do with the
> way you organize things inside context. Sure if you have to deal with car
> pieces, you've better have some neat hierachy such as
> trademark/model/year/type/engine/... or the one Martin quoted about air
> travel reservations ...

But if you are an engine manufacturer it may be more important to define engine/type/model/year/trademark if you want to know that your V16 engine was used in the 2000 version of the Ventura that General Motors issued under its Vauxhall trademark. (Context is very much dependent on the user of the information, not on its creator.)

> I can't imagine how it could be the other way round : local communities
> refering to some "general ontology" and trying to adapt it to their
> context. Which means we may have local top-down approach, inside a local
> context, but not in a "global context" if that expression makes sense. My
> opinion is that it does not make sense anyway, and the arguments for that
> are both technical and political.

Note that the context does not necessarily change the underlying ontology, but can change the order in which items in the ontology are considered relevant.

> The technical view is that whoever sets the "upper level", they are
> themselves a community (see SUO), and what they will call "general" is only
> what they suppose at the moment to be general in their implicite community
> ontology, which is *always* cultural-context biased, and will most
> certainly be irrelevant elsewhere.
> The political view is that their is no universal concept whatsoever, and
> trying to setting one is de facto trying to impose its own concept as
> universal. That's what I call "unique thought". It's an old trap we must
> always be aware of, because it's very temptative. Maybe I'm myself falling
> in it right now, you'll tell me.

But for global trading you need a "universally accepted terminology", with multiple names but one (translatable) definition.

Martin