Interactive Discourse: Influence of Problem Context 
Panel Chair's Introduction 
Barbara Grosz 
SRI International 
The purpose of the special parasession on "Interactive 
Man/Machine Discourse" is to discuss some critical 
issues in the design of (computer-based) interactive 
natural language processing systems. This panel will 
be addressing the question of how the purpose of the 
interaction, or "problem context" affects what is said 
and how it is interpreted. Each of the panel members 
brings a different orientation toward the study of 
language to this question. My hope is that looking at 
the question from these different perspectives will ex- 
pose issues critical to the study of language in gener- 
al, and to the construction of computer systems that can 
co~nunicate with people in particular. Of course, the 
issue of the influence of "problem context" is separable 
from the issue of how one might get a computer system to 
take into account the effects of this context (and, yes, 
even whether that is possible). My hope is that those 
on the panel who are concerned with the construction of 
computer-based natural language processing systems will 
address some of the issues of "how" and that all of the 
panelists will consider the prior questions of what ef- 
fects there are and what general principles underlie how 
the "problem context" influences a dialogue. 
ples. There is no taxonomy of function (as I've used 
the word). How might such a taxonomy be constructed and 
used? 
What kinds of expectations are set up by different kinds 
of functions? 
What assumptions about the knowledge, beliefs, and goals 
that are shared by the participants are made by the dif- 
ferent functions? 
How do the constraints from function interact with those 
of domain? 
What kinds of "tools" are useful for examlning such is- 
sues? (e.g., what kinds of analysis of data can be 
done)? 
What happens when expectations generated by problem con- 
text (either function or domain) are violated? 
There are two separate aspects to the "problem context" 
that influence the participants' expectations and hence 
their utterances: (i) the function of the discourse, 
and, (2) the domain of discourse. 
Function: This aspect of the problem context concerns 
why the speaker and hearer are communicating and their 
relative roles in the communication. Casual conversa- 
tions, classroom discussions, task-oriented dialogues, 
and stories have very different functions. Although it 
is most reasonable to consider computer systems as par- 
ticipating in a restricted kind of dialogue (namely, a 
dialogue which arises from aiding a person in the solu- 
tion of some problem), it is still clear that such sys- 
tems may assume different roles, e.g., that of an expert 
(user is an apprentice), tutor (student), or supplier of 
information (e.g., from a large data base). Each of the 
different functions results in different kinds of goals 
(e.g., teaching requires a different kind of informlng 
than simple question answering) and each of the differ- 
ent roles will create different expectations on the part 
of the user and different needs in terms of the kinds of 
information the system has about the user. 
Domain: This aspect concerns what a speaker is talking 
about, the subject matter of the discourse. The struc- 
ture of the information being discussed has an effect on 
the language (of. Chafe's "The Flow of Language and the 
Flow of Thought", Linde's work on apartment descriptions 
and planning, my work on focusing in task-oriented dia- 
toques). 
Both of these aspects of "problem context" have global 
effects on what gets discussed and in what "units", and 
local effects on how speakers express the information 
they convey. Clearly the two aspects interact. For ex- 
ample, what a speaker chooses to discuss next depends 
both on why he is telling the hearer and on the informa- 
tion itself and what it is related to. 
Some questions to consider: 
-~n what ways are the effects of problem context manifest 
An individual utterances and larger discourse units? 
How do people's "conversational styles" differ? 
The above discussion of "function" gave several exam- 
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