  Word sense disambiguation has developed as a sub-area of natural language
processing, as if, like parsing, it was a well-defined task which was a
pre-requisite to a wide range of language-understanding applications. First, I
review earlier work which shows that a set of senses for a word is only ever
defined relative to a particular human purpose, and that a view of word senses
as part of the linguistic furniture lacks theoretical underpinnings. Then, I
investigate whether and how word sense ambiguity is in fact a problem for
different varieties of NLP application.
