[sc34wg3] role vs. role type

[Steve Pepper]

At 06:04 19.02.2003 -0500, Patrick Durusau wrote:
>What I am not seeing is why the term "role" is being renamed as "role type?"

There has been a certain amount of confusion about this. It was finally 
agreed at some point to use both "(association) role" and "(association) 
role type" in the senses originally found in 13250. (I don't remember which 
meeting this was; SRN may remember, or will at least confirm the conclusion 
we reached.)

In 13250, an association role (represented by an <assocrl> element) 
represents the involvement of a certain topic in a certain association. It 
has a 'type' attribute which represents the class to which the role 
belongs. There is thus a kind of type-instance relationship between the 
role type and the (individual) role. A role type can be thought of as the 
set of all similar involvements in associations. Thus "husband" (for 
example) is a *role type*, not a *role*.

Roles correspond to C-nodes. Role types correspond to R-nodes. As far as I 
understand, "R" expands to "role type". This *is* confusing. I would 
suggest that the RM either sticks to the same terminology all the way, or 
else avoids it altogether.

You should look at the terminology used in the SAM, which is much closer to 
13250.

Steve

--
Steve Pepper, Chief Executive Officer <pepper@ontopia.net>
Convenor, ISO/IEC JTC1/SC34/WG3  Editor, XTM (XML Topic Maps)
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