Subject: Re: Knowledge classification systems
From: Erik Naggum <>
Date: 17 Sep 2002 21:56:30 +0000
Newsgroups: comp.lang.lisp
Message-ID: <>

* 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.