Some thoughts on classification for retrieval
Journal of Documentation, 61 (5):
571 - 581 (2005)Abstract
Purpose – This paper, originally published in 1970, considered the suggestion that classifications for
retrieval should be constructed automatically and raised some serious problems concerning the sorts
of classification which were required, and the way in which formal classification theories should be
exploited, given that a retrieval classification is required for a purpose. These difficulties had not been
sufficiently considered, and the paper, therefore, aims to attempt an analysis of them, though no
solutions of immediate application could be suggested.
Design/methodology/approach – Starting with the illustrative proposition that a polythetic,
multiple, unordered classification is required in automatic thesaurus construction, this is considered in
the context of classification in general, where eight sorts of classification can be distinguished, each
covering a range of class definitions and class-finding algorithms.
Findings – Since there is generally no natural or best classification of a set of objects as such, the
evaluation of alternative classifications requires either formal criteria of goodness of fit, or, if a
classification is required for a purpose, a precise statement of that purpose. In any case a substantive
theory of classification is needed, which does not exist; and, since sufficiently precise specifications of
retrieval requirements are also lacking, the only currently available approach to automatic
classification experiments for information retrieval is to do enough of them.
Originality/value – Gives insights into the classification of material for information retrieval.
