  In a significant minority of cases, certain pronouns, especially the pronoun
it, can be used without referring to any specific entity. This phenomenon of
pleonastic pronoun usage poses serious problems for systems aiming at even a
shallow understanding of natural language texts. In this paper, a novel
approach is proposed to identify such uses of it: the extrapositional cases are
identified using a series of queries against the web, and the cleft cases are
identified using a simple set of syntactic rules. The system is evaluated with
four sets of news articles containing 679 extrapositional cases as well as 78
cleft constructs. The identification results are comparable to those obtained
by human efforts.
