[sc34wg3] Type versus Class: settled yet?

[Mary Nishikawa]

Sorry for cross posting, but this terminology needs some discussion by WG3, too.

*Bernard Vatant
> >>BTW the use of type vs class should be made
> >>consistent at least with SAM prose, but I assume "topic type" here means
> >>"topic class")

Actually, I think we still need to come to grips with these. In Barcelona, 
we decided to replace the term "class" with "type."

So now we should be using the terms topic type, subtype, and supertype. 
While working on this draft, I found I really wanted to really use 
"class"not "type." I don't think they are interchangable in all cases.

Class of things is the set of things. Type of things is not, it is the 
category that describes the things in the set. Please comment and correct 
me if my thinking of the terms is wrong.

So we usually say, what type or (kind) of ice cream is your favorite? We do 
not say, what class of ice cream is your favorite.

The class "strawberry ice cream" could exist. The members could be all the 
varieties made by different manufacturers  of ice cream type "strawberry" 
if I wanted to create my ontology this way. Maybe I am doing a benchmarking 
study on the makers of strawberry ice cream.

There is Hagendaz strawberry ice cream which is different from Bryers, or 
the type made by the Fishkill ice cream parlor, or Subretto's gellato.

Of course, we can get complicated and some vendors may give crazy names to 
their product, but usually there is a type plain old "strawberry."

Oh, I think this might be a good example for a usage scenario, come to 
think of it.

Also, look again at this:

Date: Thu, 26 Dec 2002 18:15:38 -0500
From: Dan Brickley <danbri@w3.org>
Subject: Re: [topicmapmail] Superclass-subclass indentation in the Omnigator

*Dan Brinkley
 >>Hey, if you folks haven't picked names for these two relations yet,
 >>I hereby propose 'type' and 'subClassOf'; type relates an instance to
 >>a class it is a member of, while subClassOf is a relation between classes.
 >>FWIW these are the terms we use in RDF/S and OWL.

Since in http://www.isotopicmaps.org/tmcl/requirements we have this:

2.1 Relation to other standards

Pre-existing specifications ..... will contribute to the functional 
requirements. These include OWL ....


It would be good if we came to some agreement on the use and try make sure 
that these are crystal clear  So I am asking you to look at these 
definitions in RDF/S and OWL and comment on it. The definitions are not 
clearly defined (as far as I can see) but we need to do so ASAP. It very 
important for the TMCL.

Thanks Dan for your comment. Better late than never :)

Let's really thrash this one out. Thanks!

Cheers,
Mary
(irc nick, mariyo)