langreiter.com plain, simple: 2004-03-28-dreamCatcher

LANGREITER.COM plain, simple

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2004-03-28-dreamCatcher

CREATED BY chris • LAST EDITED BY chris 7574 days AGO

Pat Hayes: Catching the Dreams

"Considered as content languages, Description Logics are like logics with safety guards all over them. They come covered with warnings and restrictions: you cannot say things of this form, you cannot write rules like that, you cannot use arbitrary disjunctions, you cannot use negation freely, you cannot speak of classes of literals, and so on. A beginning user might ask, why all the restrictions? It's not as if any of these things are mysterious or meaningless or paradoxical, so why can't I be allowed to write them down on my web page as markup? The answer is quite revealing: if we let you do that, you could write things that our reasoning engines might be unable to handle. [...] That is what DLs are for, to ensure that large-scale industrial ontologies can be input to inference machinery and it still be possible to provide a guarantee that answers will be found, that inferential search spaces will not explode, and in general that things will go well."

"The result is that users of DAML+OIL need to take a course in how to say things in peculiar and unintuitive ways, because the safety guards prevent them from saying things naturally."

"Worrying about the complexity class of the few intricate ontologies on the web is like being obsessed with the quality of the salt in a supermarket. It is notable that almost all of the DAML so far written uses only a small part of the vocabulary of the language, and is almost entirely concerned with simple class inheritance."

Beware of Semantic Straightjackets.