Re: [topicmaps-comment] PSI for MIME types?

[Steve Pepper <pepper@ontopia.net>]

Lyndon,

At 13:04 09/07/02 +0200, Lyndon J B Nixon wrote:
>I'm wondering if there has ever been any discussion on PSIs for MIME types 
>or some other system in order to enable an application to retrieve topic 
>occurrences which are of a format that the end client can handle.

Not that I know of - yet. But this is a typical example of what we expect 
PSIs to be used for. Ideally such PSIs would be published by IANA, which is 
responsible for registering MIME types ... but that might take time. In the 
meantime, the nice thing about PSIs is that *anyone* (including you!) could 
publish them.

>I note, eg. that Ontopia used their own PSIs for the Italian Opera topic 
>map (website, desc, article as well as online/offline), but i think there 
>would be value in there being some standardized means to indicate whether 
>a ResourceRef points to a HTML document, XML, RDF, audio, video etc.

Absolutely.

Note, however, that you would probably use those PSIs in a different way 
from the Ontopia PSIs you mention: website, desc, and article are 
*occurrence types* (subjects that define classes of occurrences). MIME 
types would be properties of resources, not of the occurrence relationship 
between a resource and a topic (i.e., those properties would hold whatever 
topics the resource might happen to be an occurrence of). That being the 
case, it would make sense to model the MIME type property through an 
association between the resource and the MIME type, rather than to use 
occurrence types or scope.

Steve

--
Steve Pepper, Chief Executive 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