I’ve been throwing around (with another library programmer) the idea of expressing XOBIS as a Topic Map. He is knowledgeable about Topic Maps (TMs). I, while interested in them, wouldn’t say I’ve drunk the kool-aid quite yet.

My interest in doing this mapping of (X)OBIS into TM (Topic Map) form is to better understand how to improve XOBIS’ representation in XML (and to improve my understanding of Topic Maps in general).

I also think it is good, once you have “finished” with something (ha-ha, we are not finished yet), to reapproach it from a different angle. So, I’m looking at what TM-XOBIS (for lack of a better label) would look like.

The first thing, for me, is to reapproach TMs.

I read a little about them way back when we were doing XOBIS. To be fair, I think I was a little unjustly put off by TMs back then by a simple, and perhaps irrelevant, part of the model. By this, I mean the word “topic.”

When I looked at TMs originally, I said, “Okay, everything is a topic, but that’s not what I’m interested in… I want to talk about authorities.” I got a little too hung up on this distinction (and will set it aside for this new exploration but before I do I want to dissect it a little).

So, what is a topic? Before looking at how the TM community is using the term, let’s just look it up in a dictionary. Dictionary.COM says:

  1. The subject of a speech, essay, thesis, or discourse.
  2. A subject of discussion or conversation.
  3. A subdivision of a theme, thesis, or outline. See Synonyms at subject.
  4. Linguistics. A word or phrase in a sentence, usually providing information from previous discourse or shared knowledge, that the rest of the sentence elaborates or comments on. Also called theme.

That’s interesting and a bit provocative. I like the idea that the pursuit (and acquisition) of knowledge is just one large conversation. One might suggest that there are not objective truths (or at not ones that we can know) but, rather, just a multitude of perspectives. If a ‘topic’ is the base ‘thing’ in Topic Maps, are the TM people saying that metadata is just one large ongoing conversation… that all we have as a ‘base’ are the topics of our discourses?

From The TAO of Topic Maps: “…the topic map standard defines subject, the term used for the real world ‘thing’ that the topic itself stands in for. We might think of a ’subject’ as corresponding to what Plato called an idea. A topic, on the other hand, is like the shadow that the idea casts on the wall of Plato’s cave: It is an object within a topic map that represents a subject.”

So there is a Platonic ideal and then something that we have as a handle for the ideal. To me, it makes more sense to say that these shadows are conceptions of the ideals. Conception, from the 1913 Websters, is “The formation in the mind of an image, idea, or notion, apprehension.” A conception (e.g., concept)… doesn’t that sound more like Plato’s shadow on the wall (given that I am not a philosopher so may be missing some subtle points)?

XOBIS, like Topic Maps, has a base element. It is the Concept element. There are ten principal elements; the other nine are instantiations of particular types of Concept(s). So why did we choose those ten? Those are the ones that stood out to us as being useful in the context in which we work (metadata for institutions of cultural knowledge).

The nine instantiated XOBIS elements are divided into two classes: substantive and notional (obviously, the substantive elements are ‘handles’ for things that can be held by a library or museum and the notional elements are the shadows on the wall that have a reason for being distinguished from the other more generic shadows). Making this distinction between topic and concept, though, allows us to make another additional distinction.

These shadows, that are our handles, can be used by us in particular ways. For instance, a concept may be used as the subject (or topic) of a particular work (this is a relationship between a work and concept). If everything is a topic from the start, how does one make the distinction that the topic is being used in a topical way? A ‘topical way,’ that is, in a different sense than the idea that everything is a topic in one large ongoing conversation. Is this ‘topic’ different from a ‘topic’ being used in a categorical way? XOBIS says there is a difference.

Yes, this is quibbling and it shouldn’t have stopped me from looking at TMs. Yes, I still think Concept makes a better base object than Topic, but where do I go from there? To get around this, I’m thinking I should be thinking about all TM topics as concepts. I’ve been told it doesn’t really matter what this base element is in TMs. The important part is that there is a base element. So, in my mind, I’m going to start working with “Concept Maps” and see where it goes.