[Linguistics] - Chomsky, Noam - Three Models for the Description of Language.pdf

TIIKEE MODELS FOR TIE DESCRIPTION OF LANGUAGE*
Nom Chomsky
Department of Modern Languages and Research Laboratory of Electronics
Massachusetts Institute of Technology
Cambridge, Massachusetts
Abstract
We investigate several conceptions of observations, to show how they are interrelated,
linguistic structure to determine whether or and to predict an indefinite number of new
not they can provide simple and sreveallngs phenomena. A mathematical theory has the
grammars that generate all of the sentences additional property that predictions follow
of English and only these. We find that no rigorously from the body of theory. Similarly,
finite-state Markov process that produces a grammar is based on a finite number of observed
symbols with transition from state to state sentences (the linguist’s corpus) and it
can serve as an English grammar. Fnrthenuore, sprojectss this set to an infinite set of
the particular subclass of such processes that grammatical sentences- by establishing general
produce n-order statistical approximations to “laws”(grammatical rnles) framed in terms of
English do e closer, with increasing n, such bpothetical constructs as the particular
to matching the output of an English grammar. phonemes, words. phrases, and so on, of the
We formalisa the notions of lphrase structures language under analysis. A properly formulated
and show that this gives us a method for grammar should determine unambiguously the set
describing language which is essentially more of grammatical sentences.
powerful, though still representable as a rather
elementary type of finite-state process. Never- General linguistic theory can be viewed as
theless, it is essful only when limited to a a metatheory which is concerned with the problem
small subset of simple sentences. We study the of how to choose such a grammar in the case of
formal properties of a set of grammatical trans- each particular language on t