[topicmapmail] Questions About XTM Occurrence Semantics

[Peter P. Jones]

Hi,

Ok, I'll try again.

Assume there is an information resource on the web - an image in a 
document. As a topic map builds up three topics come into being {A, 
B,C}, each with different subject identifiers, but all of which refer to 
that image from an occurrence. In each case the occurrence referring to 
the image is in a different scope, but each occurrence has the same IRI 
value.
Topic A : Scope D : Occurrence #1 : Value IRI V
Topic B : Scope E : Occurrence #2 : Value IRI V
Topic C : Scope F : Occurrence #3 : Value IRI V

In each case, reading right to left, it is possible to say something 
like, "V in Occurrence #x in Scope Y of Topic Z addresses a specific 
appearance of the subject of Topic Z out there in the Web in image I."

But the relationship between Topic Z and the destination endpoint of the 
IRI V is simultaneously a specific arc within and from the topic map to 
the outside world.

I would then like to be able to reify one of those arcs.
That specific reference from a particular 'position' within the topic 
map is what I would like to make the subject of a reifying topic.
I want to capture being able to talk about that particular arc between a 
topic and the specific subject appearance indicated by the occurrence value.

For me, it is less about having a topic that represents the arc so that 
I can say in an association, "Jane inserted an information item with ID 
345 on May 4th, 2007," and more about having a topic that represents, 
"This particular indication within the TM of the appearance of a subject 
in the infosphere." Something that is as close as I can get to, "This 
particular pointing out of a subject."

Another way of putting it is that I want to be able to look at the 
reifying topic and know that it is talking about the 'particular 
pointing out of a subject' and not just 'arc number 345 in the TM'.

Does that make sense?

Sincerely,
Peter




Lars Marius Garshol wrote:
> 
> * Peter P. Jones
>>
>> [what reifying occurrences means]
>>
>> Ah, do you mean here that the reifying topic would carry the same IRI 
>> for its subject identifier as the occurrence value?
> 
> No. When you attach an occurrence to a topic A with a URI B there are 
> three subjects involved:
> 
>  (1) the one represented by A,
>  (2) the one referred to by B, and
>  (3) the relationship between the two.
> 
> The occurrence represents (3) (as you can see from
> 
>   http://www.isotopicmaps.org/sam/sam-model/#sect-occurrence
> 
> ), and so the reifying topic also represents (3).
> 
>> If so, that's not quite what I'm after. I'm after having the reifying 
>> topic refer to the occurrence in the TM as a _particular_ occurrence, 
>> yet also indicate that there is a distinction between auditing the 
>> insertion of an occurrence into the map and, as one way of putting it, 
>> dereferencing via the occurrence.
>> The occurrence should be the subject identifier of the reifying topic, 
>> and not the IRI, yet it matters (to me pushing this little envelope 
>> about) that somehow the intent that the IRI of the occurrence is the 
>> target rather than the ID of the occurrence element is important.
>> Another way of saying it is that I would like to be able to refer to 
>> the unique usage of the subject identifying IRI in a particular 
>> position within the TM, that particular occurrence, so that the 
>> reifying topic doesn't just identify (or merge) on the basis of where 
>> the subject identifier IRI address indicates.
>> Is that pushing things too far?
> 
> I'm sorry, but I didn't really understand any of this. Maybe I can 
> clarify some things, though:
> 
>  - There is no subject identifier here. Yes, XTM 1.0 uses the
>    <subjectIndicatorRef> element to refer to the occurrence to
>    be reified, but in the model this actually turns into a topic
>    that refers directly to the occurrence, and the URI itself
>    disappears.
> 
>  - "IRI of the occurrence" is ambiguous. Does it mean the IRI of the
>    resource that is an occurrence, or of the <occurrence> element?
> 
> The easiest way to deal with this is probably if you explain this: what 
> is your subject? What is it you want to create a topic to represent?
> 
> --Lars Marius Garshol                         Mobile: +47 98 21 55 50
> CTO, Ontopia                                Office: +47 23 23 30 83
> 
> 
> _______________________________________________
> topicmapmail mailing list
> topicmapmail at infoloom.com
> http://www.infoloom.com/mailman/listinfo/topicmapmail
> 
> 
>