Summary: Parsing By Chunks
Steven P. Abney
Bell Communications Research
November 10, 1994
I begin with an intuition: when I read a sentence, I read it a chunk at a time.
For example, the previous sentence breaks up something like this:
(1) [I begin] [with an intuition]: [when I read] [a sentence], [I read it]
[a chunk] [at a time]
These chunks correspond in some way to prosodic patterns. It appears, for
instance, that the strongest stresses in the sentence fall one to a chunk, and
pauses are most likely to fall between chunks. Chunks also represent a gram-
matical watershed of sorts. The typical chunk consists of a single content word
surrounded by a constellation of function words, matching a fixed template.
A simple context-free grammar is quite adequate to describe the structure of
chunks. By contrast, the relationships between chunks are mediated more by
lexical selection than by rigid templates. Co-occurence of chunks is determined
not just by their syntactic categories, but is sensitive to the precise words that
head them; and the order in which chunks occur is much more flexible than the
order of words within chunks.