  Current definitions of notions of lexical density and semantic weight are
based on the division of words into closed and open classes, and on intuition.
This paper develops a computationally tractable definition of semantic weight,
concentrating on what it means for a word to be semantically light; the
definition involves looking at the frequency of a word in particular syntactic
constructions which are indicative of lightness. Verbs such as "make" and
"take", when they function as support verbs, are often considered to be
semantically light. To test our definition, we carried out an experiment based
on that of Grefenstette and Teufel (1995), where we automatically identify
light instances of these words in a corpus; this was done by incorporating our
frequency-related definition of semantic weight into a statistical approach
similar to that of Grefenstette and Teufel. The results show that this is a
plausible definition of semantic lightness for verbs, which can possibly be
extended to defining semantic lightness for other classes of words.
