xml-dev - Re: "RDF + Topic Maps" = The Future

[URAMOTO Naohiko <uramoto@trl.ibm.co.jp>]

Hi,

I'm very interested in the difference between RDF and TM in terms of express
ing power
to use them together or merge them.

For example, suppose we want to express the following statement:

"The Hamlet is (was) written by Shakespeare."  

and let me express it by using RDF and TM (please correct if the description
s are wrong).

RDF expression (namespace is ignored):

<Description ID="hamlet">...</Description>
<Description ID="shakespeare">...</Description>

<Description about="#hamlet">
     <written-by resource="#shakespeare"/>
</Desciprion>

TopicMap expression:

 <topic id="hamlet"><instanceOf> ...</instanceOf> </topic>
 <topic id="shakespeare"><instanceOf> ...</instanceOf></topic>

<association>
   <instanceOf><topicRef xlink:href="#written-by"/></instanceOf>
   <member>
       <roleSpec><topicRef xlink:href="#author"/></roleSpec>
       <topicRef xlink:href="#shakespeare"/>
   </member>      
   <member>
       <roleSpec><topicRef xlink:href="#work"/></roleSpec>
       <topicRef xlink:href="#hamlet"/>
   </member>      

The TopicMap example provides roles for of two topics associated by "written
-by", while
the RDF example cannot. However, I think it is possible to express them by d
efining
domain and range constraints which is the RDF Schema vocabulary.

<rdfs:Property ID="written-by">
  <rdfs:domain rdfs:resource="#work">
  <rdfs:range   rdfs:resource="#author">
</rdfs:Property>

My question is what is the essential difference between RDF and TM...


At 13:24 2000/12/14 -0800, Lisa Rein wrote:
Lisa> Hello all :-)
Lisa> 
Lisa> It's not a question of which one is better.
Lisa> 
Lisa> It's a question of figuring out what we want to do first, now
Lisa> that we are going to be able to use them together.
Lisa> 
Lisa> It's downright exciting!
Lisa> 
Lisa> lisa
Lisa>  
Naohiko URAMOTO
uramoto@trl.ibm.co.jp, uramoto@jp.ibm.com
Tokyo Research Laboratory, IBM Research, and
National Institute of Informatics