Re: An intuition pump

>I'm going to use QNames to abbreviate URIs. Assume each prefix 
>univocally expands to a distinct namespace URI.
>
>Sally the ontologist defines some terms, including sally:Person 
>which is, in her ontology, exclusively the unionOf wordnet:woman and 
>wordnet:man. And suppose further, sally:RightsHolder is a subClassOf 
>sally:Person.
>
>Now, it's not even exactly clear that Sally is using the two wordnet 
>terms correctly, but grant that she is. People use Sally's term all 
>over the place. It's adopted by that powerful vocabulary juggernaut, 
>FOAF, and thus becomes the *de facto* standard for talking about 
>persons.
>
>Now Molly comes along and notes the extreme chauvinism of Sally's 
>definition, excluding as it does (arguably) eunuchs, hermaphrodites, 
>intelligent programs, chimps, augmented chimps, Martians and the 
>like. Molly proposes an alternative ontology for sally:Person.
>
>Now, if I understand the view as raised by tim in his issuing, Molly 
>and the Foafsters are pretty much stuck. sally:Person just *means* 
>whatever Sally wants it to mean.

Well, it does mean that, but they are not stuck. Molly can introduce 
molly:person, a superClass of sally:person, tell people what it 
means, and then folk can use that. If enough people feel that this is 
the best definition, it will presumably get used more widely and will 
become the de facto new standard, maybe. More likely, two rival 
communities will emerge, the Mollyites and the Sallieties, with 
rather different views about what constitutes a person. What did you 
expect, that the entire world was going to agree about what words 
mean?? (Try 'marriage'.)

The ontological reasoners have at least a chance of not getting 
confused, because they have names for both concepts and an idea of 
the relationship between them. I don't see this as being a 
problematical kind of example; on the contrary, in fact: it shows (in 
a simplified caricature) how a nuanced vocabulary can arise from 
people being obliged by the conventions of ownership to define 
relationships between concept meanings. Contrast this with the case 
where nobody can really say what a URI is supposed to mean, and when 
Molly used sally:person in a nonstandard way, that (mis?)use just 
kind of back-taints all the other uses, so that even Sally's ontology 
doesn't mean what she intended it to mean any more. Now, *that* 
really is a recipe for world-wide confusion.

>More interestingly, suppose Sally had just been a bit careless and 
>really was aiming at a more expansive notion of Person, just blew 
>it. However, before Molly detected the problem, Sally sold her now 
>very popular domain to People for a Very Narrow Sense of People in 
>Foaf Documents (PVNSPFD). They refuse to change sally:Person.
>
>Now, what concept does sally:Person identify? When? Does it matter?

I would say : whatever PVNSPFD claims it does: because they own the 
URI (now). However, I doubt if they would have any motivation, having 
paid for the damn thing, to alter its meaning (or at least, not 
without widely disseminating this intended change) since to do so 
would only confuse their user base. So, it would likely retain its 
meaning. Yes, it does matter.

>Is there anything Wrong with Molly (or *Sally*) putting out an 
>alternative ontology, and the Foaf x.x ontology switch its 
>owl:imports statement to point to the alt-ontology instead of the 
>(now owned by) PVNSPFD one.

Ah, that indeed raises a nasty issue about 'versions' of ontologies 
and the real meaning of importing. But that issue just IS nasty: it 
is almost as nasty when phrased purely syntactically as when it is 
phrased semantically.  So think that is a red herring.

Pat

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Received on Sunday, 21 September 2003 17:45:20 UTC