[23 November 2009]
In Leipzig earlier this month, at TMRA 2009, there was (understandably, in light of the conference motto “Linked Topic Maps”) a certain amount of discussion of using public subject identifiers for topics, to increase the likelihood that information collected by different people could be merged usefully, without preconcertation by the parties involved. In principle, this raises all sorts of thorny questions about ontology (of both the philosophical and the engineering kinds). In practice, however, people would like to be able build systems and share data without waiting for the philosophers and engineers of the world to agree on an answer to the question ”What exists?” and they seem to be willing to risk making a mistake or two along the way.
At some point (I’m now a bit hazy when this happened), someone mentioned a proposal made by Vegard Sandvold, an interesting sort of rough-and-ready approach to the problem: use Wikipedia (or dbpedia) as a sort of barometer of a reasonably democratic consensus on the question.
Steve Pepper has responded that one problem with that (among others of no concern here) is that if he wants to say something about (for example) the International Socialists organization in the UK (founded in 1962), a restriction to Wikipedia as a source of public subject identifiers would make it impossible: Wikipedia redirects from International Socialists (UK) to a page about the Socialist Workers Party (Britain). This organization, founded in 1977, is really not the same thing, said Steve (even if Wikipedia says the SWP was formed by renaming the IS, which suggests a continuity of essential identity).
Steve appears to argue that there is a simple fact of the matter in this case, and that treating the International Socialists and the Socialist Workers Party as the same is simply wrong. He may be right. But (without wanting to argue the ins and outs of this particular case) the example seems to me to be the kind of question which does not always have a determinate answer. It illustrates nicely a kind of ontological indeterminacy which necessarily haunts both RDF and Topic Maps and shows why accounts of how those technologies can combine information from multiple sources can strike careful readers as naive.
Within a given discourse, for a given purpose, we may decide to analyse a particular portion of reality as consisting of several distinct entities which succeed each other in time; in another discourse, for another purpose, we may choose to analyse that same portion of reality as consisting of a single entity which undergoes some changes of (accidental) properties. Concretely: sometimes we want to treat the International Socialists as distinct from the Socialist Workers Party, and sometimes we want to treat them as two names for the same thing. Sometimes I want to treat the journal Computers and the Humanities and the journal Language resources and evaluation as two quite distinct journals; at other times, I want to treat them as the same journal, published under one title through 2004 and then under a new title. There is not a simple fact of the matter; it depends on what, exactly, I want to refer to when I refer to things.
It reminds me of W.V.O. Quine’s question: if a field linguist sees a rabbit run by and hears a native informant say “gavagai”, how is the linguist to determine whether this utterance means ‘Look, a rabbit!‘ or ‘Food!’ or ‘Undetached rabbit-parts’? Quine talked about the indeterminacy of translation, suggesting that he’s concerned essentially with the problem of understanding what someone else really means by something (oddly, he seems to think the difficulty arises primarily with foreign languages, which seems to me optimistic), but I think the difficulty reflects the fact that the field linguist is likely to confront an analysis of reality that does not match his own. This happens to the rest of us, too, not just to field linguists.
When I say the phrase “International Socialists (UK)”, can you reliably determine whether I intend to denote an organization which ceased to exist in 1977, or an organization which continues to exist today?
You can ask me, of course, and maybe I’ll answer. And if I answer, maybe I’ll tell you the truth. But if you don’t have a chance to ask me?