[xtm-wg] RE: [topicmapmail] Smalltalk Implementation of Topic Maps

["W.M. Jaworski" <wmj@gen-strategies.com>]

[Steve Pepper]
the statement that "scopes apply to both topics and associations"
could be misinterpreted.
Scope applies to *topic characteristics*, i.e. names, occurrences
and (roles played in) associations.

[WMJ]

(1) topic ::= object (like in OO)
(2) "topic characteristics" ::= object properties
(3) topic role ::= object property
(4) topic scope ::= properties' domain

I am not sure about (1) .. (4). Please correct.

I am more comfortable with:

Topic map ::= map of (overloaded) associations
scope ::= cluster of (overloaded) association
scope::= context

Why (overloaded) associations? Why (overloaded) nodes?
"Proof of pudding is with eating". Did anybody try on a sizable topic map?

Regards

WMJ


-----Original Message-----
From: topicmapmail-admin@infoloom.com
[mailto:topicmapmail-admin@infoloom.com]On Behalf Of Steve Pepper
Sent: Thursday, April 26, 2001 4:35 PM
To: topicmapmail@infoloom.com; xtm-wg@yahoogroups.com
Subject: Re: [topicmapmail] Smalltalk Implementation of Topic Maps


At 08:26 26.04.2001 +0100, Martin Bryan wrote:
>Your modelling of scopes is not correct. Scopes apply to both topics and
>associations. They are fundamental to both. They are not just for added
>themes, but have a fundamental role in providing views of data. You should
>model based on ISO13250 rather than XTM, which simplifies things somewhat.
>If you model based on the full set  then you can apply the XTM
>simplifications later.

I wouldn't presume to correct one of the editors of ISO 13250 :-)
but the statement that "scopes apply to both topics and associations"
could be misinterpreted.

Scope applies to *topic characteristics*, i.e. names, occurrences
and (roles played in) associations.

ISO 13250 provides syntactic shortcuts for specifying themes
at the level of the topicmap element and the topic element such
that they propagate down and extend the scope on the relevant
characteristics.

Specifying a scope attribute on the topicmap element adds the
themes (or scoping topics) to *all* characteristics in the whole
topic map. Specifying a scope attribute on a topic element adds
the themes to the name and occurrence characteristics specified
through corresponding subelements of that topic element.

XTM does not have this syntactic shortcut, although it does have
the other one, namely that scope is specified on the association
element rather than the individual roles.

[Interesting issue that I've never heard raised before: Say we
have two topics, A and B. A has a [scope] attribute on the
topic element that specifies theme X. B has a characteristic
Y, which might be a name or an occurrence. If A and B are merged
due to the topic naming constraint or subject identity mechanism,
does X get added to the scope of Y? My take on this is that it
doesn't. Since this is a purely syntactic mechanism it should
only have effect at the point in the processing at which the
syntax is turned into the internal data representation. By the
time merging takes place it should no longer be there.]

Steve
--
Steve Pepper, Chief Technology Officer <pepper@ontopia.net>
Convenor, ISO/IEC JTC1/SC34/WG3  Editor, XTM (XML Topic Maps)
Ontopia AS, Waldemar Thranes gt. 98, N-0175 Oslo, Norway.
http://www.ontopia.net/ phone: +47-23233080 GSM: +47-90827246

_______________________________________________
topicmapmail mailing list
topicmapmail@infoloom.com
http://www.infoloom.com/mailman/listinfo/topicmapmail

To Post a message, send it to:   xtm-wg@eGroups.com

To Unsubscribe, send a blank message to: xtm-wg-unsubscribe@eGroups.com 

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/