Next: Homonymy vs. Polysemy
Up: Computational Issues
Previous: What we want from
The fundamental problem posed by polysemy for computation is that
particular words can take on an almost indefinite number of subtle
meaning variations. These variations can stem
from regular sense extension processes, be induced by contextual
factors, or result from metaphorical or metonymic extensions. The
lexicon is not fixed; word use is flexible and generative. This runs
counter to the greatest part of NLP systems, which require every entry
in the lexicon to be specified in advance and all potentially relevant
sense distinctions to be permanently encoded. We saw in the previous
section that for many applications a fixed view of the lexicon is
adequate, but as more sophisticated processing of natural language
becomes necessary the effectiveness of this approach to lexicon design
quickly diminishes. It simply does not reflect the creativity which
pervades word use. Let us consider some of the reasons why.