10 Aug 2004
CS 5244: Orientation
53/32
Boolean Model
¡Query
processing strategy:
lJoin
less frequent terms first
lEven in ORs, as merging takes longer than lookup
¡Problems
with Boolean model:
lRetrieves
too many or too few documents
lLonger
documents are tend to match more often
because they have a larger vocabulary
lNeed
ranked retrieval to help out