[sc34wg3] SAM-issue term-scope-def
Graham Moore
sc34wg3@isotopicmaps.org
Fri, 14 Jun 2002 08:37:14 +0100
Hi,=20
Bernard I think I share your position here - I think this is effectively =
what I said in my small paper on Is Scope Bogus? i.e. that scope is no =
more than a lazy way of stating things about associations and that =
really to be useful associations should be further qualified by other =
associations.
I would like us to try and get some consensus on this idea and put =
something into the spec to reflect this. I dont think we need to ditch =
scope just make it very clear that its a sloopy way to work. I think we =
do this by defining something like the scope assoc example bernard =
provided and say 'this is what scope is, but as you can see its not very =
expressive'. Users of topics maps will then have all the info about =
whats really going on and if they want fairly useless bags of topics =
then fine, if not we'll have much better maps.
I also think this goes hand in hand with ditching the topic naming =
constraint as a MUST do and introducing typed names instead of scoped =
names.
If I can give a short example about the names,
topic t1 has name n1.
n1 has scope of (t2, t3)
Scope on names is used in 2 ways:
1. to type
2. to qualify the topic
i.e.=20
'gra' scoped by {shortname} is a typing action
'granada' scoped by {city} is a topic qualifying action
I think that in the first circmstance what you are doing is typing the =
name. The second example is just awful - what is really being said here =
is that the TOPIC not the name has some relationship with 'city'.
I would like to see that when someone queries a map with a topic name =
they can get back multple topics.
i.e query =3D> get topics by name 'Washington'
Washington (located England)
Washington (located US)
and I would be horrified if all the names of these topics were scoped by =
some topic that should really be associated properly with the topic.
gra=20
-----Original Message-----
From: Bernard Vatant [mailto:bernard.vatant@mondeca.com]
Sent: 13 June 2002 07:54
To: sc34wg3@isotopicmaps.org
Subject: Re: [sc34wg3] SAM-issue term-scope-def
Hello all.
Lars Marius asked me on another forum to bite here. Well, I was very =
uneasy with that
issue until yesterday night, then I got the following idea(s), which =
maybe could help.
Sorry, it's a bit long. But I tried to be very explicit. Thanks for your =
time and
attention.
I've figured so far scope as a bag where you could put so many different =
things that no
general rule how to process it could be really set, other than arbitrary =
or "less evil",
as Lars Marius tried to figure below . But in fact there is a way to =
entangle that, if you
begin by expliciting the implicit (meta)association expressed by scope. =
The role-players
of this (meta)association are:
1. The scoped assertion itself (reified)
2. The elements of the scope set (scoping topics)
Note that "assertion" in 1 is to be understood in the most generic =
sense: any assertion
that can be scoped, including regular associations, topic-name and =
topic-occurrence
associations.
If the role of the first member (assertion) is clearly specified =
(scoped), the role of the
scoping members are not specified, further than "scoping" ... which is a =
very poor
semantic indeed. That's where the issue comes from. If you specify, like =
in any regular
association, the role of scoping topics, things become clearer and the =
conclusion is
easier to draw and quite natural.
Let's take an example. "Henry is King of Navarre and King of France from =
1589 to 1610"
Express that using the basic assertion "Henry is King", the rest of =
information being
expressed as scopes. Note BTW that this assertion can be expressed like =
a regular
association between Henri (person) and a status (King), or the =
attachment of a name
(Henri) to a topic (King) ... and that it does not matter in fact. In =
any case, we have
three scoping elements : France, Navarre, and the time span.
Clearly, the two former have a "space" role, and the latter a "time" =
role in the scoping
meta-association. So if you express it explicitly, quite obviously you =
have the following
members:
{Henri is King} (scoped assertion)
{France, Navarre} (space scope)
{1589-1610} (time scope)
Now it figures that scopes playing the same role are first gathered by a =
"OR" (union?),
and resulting sets (members) are gathered by a "AND" (intersection?) to =
get the global
scope. More precisely:
"Henri is King" is valid if ("space belongs to Navarre" OR "space =
belongs to France") AND
"time belongs to 1589-1610".
It figures another thing. Asserting a scope seems to be in that case =
setting implicitly
the domain of two variables, "space" and "time". The nature of those =
variables are
expressed by the role specifications in the meta-association.
If we try to draw a general rule for that:
If : the scope set is S =3D {Ai, Bi, ..., Xi, ...}
where A, B, ..., X are scoping variables and Ai, Bi, ..., Xi values of =
those variables.
Then : the scoped assertion is valid if
AND( A belongs to {Ai} , B belongs to {Bi} ... X belongs to {Xi} )
It seems that this is very generic, the scoping variable-role, besides =
time and space,
could be language, source, thesaurus, market sector ... whatever. Of =
course, this rule can
be applied if roles of scoping elements are specified. Maybe the =
standard should be
extended to include that? From a syntax viewpoint, it would mean =
allowing <member> as
child of <scope> ... Sorry to speak syntax here :))
What about now unconstrained scope and merging? The original source(s) =
of merging being
added to scopes as reified topic maps in the merged map, as I suggested =
in a previous
post, seems consistent with that. The original topic map plays role =
"source". In the above
example, you could add to scope that the assertion (unauthorized) source =
is "TM-BV".
So, after merging, you would have another member in the scoping =
meta-association:
{Henri is King} (scoped assertion)
{France, Navarre} (space scope)
{1589-1610} (time scope)
{BV} (source scope)
If you have the same assertion confirmed by "Larousse 1972" (just =
checked), this will be
added to the source member:
{Henri is King} (scoped assertion)
{France, Navarre} (space scope)
{1589-1610} (time scope)
{BV, Larousse} (source scope)
Well. I think that makes it for my 0.02 Euros.
Bernard
-------------------------------------------------------------------
Bernard Vatant
Consultant - Mondeca
www.mondeca.com
Chair - OASIS TM PubSubj Technical Committee
www.oasis-open.org/committees/tm-pubsubj/
-------------------------------------------------------------------
----- Message d'origine -----
De : "Lars Marius Garshol" <larsga@garshol.priv.no>
=C0 : <sc34wg3@isotopicmaps.org>
Envoy=E9 : dimanche 9 juin 2002 19:45
Objet : [sc34wg3] SAM-issue term-scope-def
>
> In ISO 13250 the definition of scope says that scope is the union of
> the themes. That is,
>
> [finland =3D "Finland" / norwegian swedish]
>
> means that the name "Finland" is valid in Norwegian and that it is
> also valid in Swedish.
>
> XTM 1.0, on the other hand says that it is up to the application how
> to interpret the scope.
>
> The current SAM version[1] says scope is the intersection of the
> themes, which means that this particular scope would only be valid in
> *both* Norwegian *and* Swedish at the same time, which would require
> the topic to be written in this way:
>
> [finland =3D "Finland" / norwegian
> =3D "Finland" / swedish]
>
> On the other hand, that something is my opinion today could according
> to the SAM be expressed by scoping it with topics representing me and
> today. ISO 13250 explains in a note that to say this would require a
> topic representing me today would have to be created and used as the
> scope. (No mechanism is provided for doing so in ISO 13250, however.)
>
>
> The question is, which of these three approaches should we choose? I
> think we need to consider carefully the consequences for the
> unconstrained scope, for merging, and also for querying operations.
>
>
> --- Scope is union
>
> If we say that scope is union that would mean that the following topic
>
> [finland =3D "Finland" / norwegian swedish
> =3D "Finland" / norwegian
> =3D "Finland" / swedish]
>
> contains two redundancies, and is actually equivalent to
>
> [finland =3D "Finland" / norwegian swedish]
>
> which would seem to imply that the rules for equivalence and
> redundancy elimination need to be modified.
>
> Furthermore, if associations with published subjects are necessary to
> form compound scope it means that in order to answer the question
> "what occurrences of the topic 'term-scope-def' are valid in the scope
> 'lmg'" correctly when presented with
>
> {term-scope-def, opinion, ""} / lmg-today
>
> the topic map processor would have to traverse associations to
> evaluate the scope correctly, and building compound scopes becomes
> very cumbersome.
>
>
> --- Scope is intersection
>
> This means that to assert that something is valid in two different
> contexts requires it to be repeated. This seems like the lesser evil.
> It also means that the arithmetic of scope works well with the
> unconstrained scope being the empty set. (See previous email.)
>
>
> --- Scope is unspecified
>
> One of the mechanisms for merging (TNC merging) would then depend on a
> feature whose meaning is unspecified. Furthermore, when attempting to
> merge topic maps that interpreted scope differently one would be bound
> to get suboptimal results. Furthermore, we would have to create TMQL
> scope operators for a construct whose interpretation is undefined.
>
> In short, this does not seem to work very well.
>
>
> [1] Versions of SAM prior to 1.23 had an editorial error in the
> definition of scope.
>
> --
> Lars Marius Garshol, Ontopian <URL: http://www.ontopia.net >
> ISO SC34/WG3, OASIS GeoLang TC <URL: http://www.garshol.priv.no =
>
>
> _______________________________________________
> sc34wg3 mailing list
> sc34wg3@isotopicmaps.org
> http://www.isotopicmaps.org/mailman/listinfo/sc34wg3
>
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