Subject: Re: Knowledge classification systems From: Erik Naggum <firstname.lastname@example.org> Date: 17 Sep 2002 21:56:30 +0000 Newsgroups: comp.lang.lisp Message-ID: <email@example.com> * Don Geddis | Does this mean that a given Dewey classification encodes multiple attributes? Yes. Geography and audience are particularly well-utilized examples. E.g., a book about Indiana high-school women's basketball would be classified under sports, basketball, pre-college, in Indiana, for women. A book about cats for children would be classified under cats, intended for children. | Please correct me if I'm wrong, but I assume that the Dewey system (and the | others you've mentioned) are designed for physical objects like books, where | each item belongs in exactly one place. Yes, the books would be in one place, but you would obviously have multiple index cards for them if they were cross-classified. It is useful to find related items grouped in the bookshelves, but this is a consequence of the nature of bookshelves, not of the classification. | With online systems, it would seem much better to label each data item with | a whole set of applicable features, and then basically navigate through the | hierarchy by doing searches and building virtual indexes. In such a scheme, | a given object might appear at numerous "leafs" in the classification tree, | rather than only one. This is already the case. I have several books that are cross-classified. | Do Dewey systems already allow for this somehow? Or do you think the idea | that an item might not have a unique classification is misguided? I think you have assumed that a classified item has only one classification. This is false. It must have one, and the better it is, the more useful that one is, but if a book covers some more than subject, there is nothing to stop it from getting several classifications. (Unless, of course, it is a "general collection", where the classifiers basically give up on it with the assumption that people would not look for it under any specific area. -- Erik Naggum, Oslo, Norway Act from reason, and failure makes you rethink and study harder. Act from faith, and failure makes you blame someone and push harder.