MIT Encyclopedia of the Cognitive Sciences - Cryptome

Development
See COGNITIVE DEVELOPMENT; INFANT COGNITION; NATIV-
ISM; NEURAL DEVELOPMENT
Developmental Language Disorders
See LANGUAGE IMPAIRMENT, DEVELOPMENTAL
Diachrony
See PARAMETER-SETTING APPROACHES TO ACQUISITION,
CREOLIZATION, AND DIACHRONY
Discourse
Discourse is the ground of our experience of language and
of linguistic meaning. It is in discourse that we learn language
as children, and in discourse that we most adequately
convey our thought. The individual utterances in a discourse
are notoriously vague and full of potential AMBIGUITY. Yet
in the context of the discourse in which they occur, vagueness
and ambiguity are rarely a problem. That is, the overall
discourse profoundly influences the interpretation of individual
linguistic constituents within it, as witnessed by our
discomfort with the ethics of taking what someone says out
of context.
Discourse can be characterized in three principal ways.
We may think of discourse as a type of event, in which
human agents engage in a verbal exchange; in the limit
case, the monologue, there is only one agent, but even
then there is an intended audience, if only reflexive or
imaginary. We may also think of discourse as the linguistic
content of that exchange, an ordered string of words
with their associated syntactic and prosodic structures. Or
we may characterize discourse as the more complex structure
of information that is presupposed and/or conveyed
by the interlocutors during the course of the discourse
event in view of the explicit linguistic content of the
exchange. The information structure of a discourse may be
characterized as an ordered set containing several distinguished
kinds of information, for example: a set of discourse
participants (the interlocutors); the linguistic
content of the discourse, with each utterance indexed by
the speaker; the information presupposed or proffered by
speakers during the discourse via the linguistic content of
their utterances; an association of the proffered information
with various topics or questions under discussion, the
topics and subtopics hierarchically organized by virtue of
their relations to the (often only inferred) goals and intentions
of the various speakers (the intentional structure of
the discourse); a set of entities discussed (the domain of
discourse); a changing set of the entities and topics which
the interlocutors focus on during their discussion, organized
as a function of time (the attentional structure of
discourse); and other kinds of information and structures
on information, as well (Lewis 1979; Grosz and Sidner
Discourse 231
1986; Roberts 1996). The information structure of a discourse
is far richer than its linguistic content alone. Only
the full range of contextual information for a given discourse,
including a grasp of the interlocutors’ inferred
intentions, the intended rhetorical relations among their
utterances, and other nonlinguistically given information
that they share, can resolve all the potential ambiguities in
the linguistic strings uttered, clarify the often inexplicit
connections between utterances, and lead us to grasp what
the speaker(s) intend to convey.
These three ways of characterizing discourse—as an
event revolving around verbal exchange, as the linguistic
content of that exchange, and as the structure on the information
involved—are not mutually exclusive; there is no
verbal exchange without linguistic content, and the latter
can be taken as one aspect of the abstract information structure
of the exchange. However, most of the work on discourse
in artificial intelligence, linguistics, philosophy of
language, PSYCHOLINGUISTICS, sociology, and anthropology
can be classified according to which of the three aspects it
focuses on. For example, sociologists, sociolinguists, and
ethnographers interested in conversational analysis (Sacks,
Schegloff, and Jefferson 1978) focus on the discourse event
itself and its social character, including the way that interlocutors
organize their participation in such events in an
orderly, apparently conventional manner, varying somewhat
from culture to culture. Speakers take turns, the opportunity
for taking a turn being cued by a number of conventional
means (including set phrases, intonation, and pauses), and
negotiate the beginning and end of a discourse as well as the
shift from topic to topic within it. In sociologically informed
anthropological linguistics (Duranti 1997), discourse events
are taken to play a crucial role in the creation, reproduction,
and legitimation of a community’s social alliances and
cleavages. Those working in the tradition of discourse analysis
(see van Dijk 1985; Carlson 1983) focus instead on the
linguistic content of the verbal exchange, the text, some
arguing that it is generated by the syntactic rules of a text
grammar. But probably the majority of theorists who work
on discourse today would agree that discourse is not a linguistic
structure generated by a grammar, but instead is
structured by nonlinguistic, logical, and intentional factors—aspects
of what we have called the information structure
of discourse.
A number of prima facie unrelated pragmatic phenomena
depend on the information structure of discourse, suggesting
that this aspect of discourse can provide the basis for a unified
theory of the role of pragmatic factors in linguistic interpretation.
Dynamic theories of semantic interpretation take
the meaning of an utterance to be a function from contexts
(the context of utterance) to contexts (the context of utterance
updated with the information proffered in the utterance).
One can view the three basic types of speech acts—
assertions, questions, and orders—as functions that update
the information structure of a discourse in different ways.
Assertions update the information proffered in the discourse
(see DYNAMIC SEMANTICS; Stalnaker 1979); a question sets
up a new (sub)topic for discussion, hence affecting the intentional
structure of the discourse (Ginzburg 1996; Roberts
1996); an order, if accepted, commits the person ordered to