Table Of ContentQUESTIONS AND ANSWERS
LINGUISTIC CALCULATION
Published by Reidel in cooperation with KV AL.
Managing Editors:
HANS KARLGREN, Stockholm
FERENC KIEFER, Budapest and Stockholm
Editors:
LENNART AQVIST, Uppsala
NICHOLAS BELKIN, London
ARA VIND JOSHI, Philadelphia
MAR TIN KAY, Palo Alto
RAINER KUHLEN, Konstanz
JURGEN KUNZE, Berlin, D.D.R.
MAKOTO NAGAO, Kyoto
PETR SGALL, Prague
DON WALKER,MenloPark
DIETER WUNDERLICH, Dusseldorf
VOLUME 1
QUESTIONS
AND
ANSWERS
Edited by
FERENC KIEFER
D. Reidel Publishing Company
A MEMBER OF THE KLUWER ACADEMIC PUBLISHERS GROUP
Dordrecht / Boston / Lancaster
library of Congress Cataloging in Publication Data
Main entry under title:
Questions and answers.
(Linguistic calculation; v. 1)
Papers from a conference held in Visegnid, Hungary, in May 1980.
Includes index.
1. Grammar, Comparative and general-Interrogative-Congresses.
2. Semantics-Congresses. 3. Language and logic-Congresses.
4. Information storage and retrieval systems-Congresses. I. Kiefer,
Ferenc. II. Series.
P299.157Q38 1983 415 83-9544
ISBN-13: 978-94-009-7018-2 e-ISBN-13: 978-94-009-7016-8
DOl: 10. I 007/978-94-009-70 16-8
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Copyright © 1983 by D. Reidel Publishing Company, Dordrecht, Holland
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No part of the material protected by this copyright notice may be reproduced or
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TABLE OF CONTENTS
FERENC KIEFER / Introduction
LENNART AQVIST / On the "Tell Me Truly" Approach to the
Analysis of Interrogatives 9
MONIKA DOHERTY / The Epistemic Meaning of Questions and
Statements 15
GUNTHER GREWENDORF / What Answers Can Be Given? 45
EV A HAJICOV A / On Some Aspects of Presuppositions of Questions 85
ROLAND R. HAUSSER / The Syntax and Semantics of English
Mood 97
JAAKKO HINTlKKA /New Foundations for a Theory of Questions
and Answers 159
J. HOEPELMAN / On Questions 191
ARAVIND K. JOSHI/Varieties of Cooperative Responses in
Question-Answer Systems 229
MANFRED PINKAL / Questions of Believing 241
PETR SGALL / Relevance of Topic and Focus for Automatic
Question Answering 257
HANS KARLGREN and DONALD E. WALKER / The Poly text
System - A New Design for a Text Retrieval System 273
INDEX 295
Ferenc Kiefer
Introduction
In almost all principled accounts of questions questions are related to
the corresponding answers. Zellig Harris (Harris 1978:1), for example,
maintains that" ... all interrogative sentences can be derived, by means
of the independently established transformations of the language, from
sentences which assert that someone is asking about a disjunction of
statements which are the relevant possible answers to that interroga
tive." This amounts to the claim that a yes-no question such as Will
John stay? is derived from I ask you whether John will stay and a wh
question such as Who came is derived from something like I ask you
whether A came or B came or. .. or X came ..
Though in generative grammar interrogatives are not derived from
the corresponding declaratives, the semantic interpretation of questions
is akin to the syntactic source of questions posited by Harris. Jerrold
J.Katz and Paul M.Postal (Katz-Postal 1964:113-117) state a reading
rule for Q, the interrogative constituent, which boils down to (1) in the
case of yes-no questions and to (2) in the case of wh-questions.
(1) Tell me which of the following is true: John will stay or John will
not stay.
(2) Tell me which of the following is true: A came or B came or ... or
X came.
Thus, the semantic interpretation of questions makes reference to the
set of possible answers represented here by a disjunction of statements.
In logical analyses of questions answers appear quite naturally in the
accounts. For questions do not represent propositions and therefore
they cannot be assigned truth values. Answers, on the other hand, are
formally declarative sentences and do represent propositions and thus
can be true or false. It does not come as a surprise, then, that for a
logician the meaning of a question is most naturally the set of all its
possible answers. In other words, on this approach, a question denotes
the set of propositions which are possible answers to it. One may also
take a somewhat more restricted view and maintain that the meaning of
a questions is the set of all its true answers. This approach is often
Ferenc Kiefer (ed.), Questions and Answers, 1-8.
Copyright © 1983 by D. Reidel Publishing Company
2 FERENC KIEFER
referred to as the propositional approach to the semantics of questions.
A yes-no question is identified with a set consisting of two propositions,
one being the negation of the other, an alternative question with a set of
propositions representing the alternatives, and, finally, a wh-question
with a set of propositions which represent all the possible answers to the
question, where "possible answer" means that the question word is
replaced by an individual constant. If the meaning of a question is
identified with its true answers only true propositions may count as
possible answers.
The second approach, often called categorial approach, assumes that
questions are functions from categorial answers to propositions. On
this approach the yes-no question Will John stay? is analyzed as
where the variable Xm stands for "yes" or "no". And a question such
as Who came? can be analyzed as
This approach is based on the observation that the question word
must be replaced in the answer by a constituent belonging to the same
category and that an answer turns a question into a proposition. Notice
that on the categorial approach questions are not identified with
propositions though propositions are the final outcome of the analysis.
There is also a third approach which may be called the epistemic
imperative approach. On this approach the question Will John stay? is
analyzed as
Bring it about that I know that John will stay or that I know that
John will not stay.
For the alternative question Will John or Bill stay? we get the
Bring it about that I know that John will stay or that I know that Bill
will stay.
And, finally, the wh-question Who came? is analyzed as
Bring it about that I know who came.
INTRODUCTION 3
Questions can thus formally be represented by means of the imperative
operator! and the epistemic predicate K ( = know). Thus, for example,
for alternative questions with two alternatives the following identity
holds:
?(p,q) = !(Kp v Kq)
where ? is the question operator and p and q represent the two
alternatives. (Cr. Hoepelman, this volume).
The set of possible answers will essentially depend on the logic on
which the logic of questions is based. In other words, in logical systems
the class of answers is determined by the question and, vice versa, the
question is uniquely determined by the class of answers.
The relationship between question and corresponding answer seems
to be quite straight froward , not to say simple, in logical analyses.
However, the logical paradise is quickly lost, as Henry Hiz puts it (Hiz
1978: XII), when we inquire into the precise relationship between logical
structures and actual questions in natural language. Leaving aside the
question of how to derive natural language questions from logical
forms-which poses particular problems of its own-it has to be
determined what constitutes, semantically and pragmatically speaking,
a question-answer pair in natural language. In grammar most accounts
stipulated thus far would only allow for direct answers to a question.
Though the notion of direct answer depends on the approach chosen,
most accounts would consider the full answer Yes, John will stay and
the elliptical answers Yes, he will and Yes as direct answers to the
question Will John stay? In the case of a question such as Who came?
the set of direct answers would consist of John came and John.
The first problem arises if we consider "yes" and "no" as represent
ing direct answers. Answering the question Won't John stay? with
"no" amounts to the assertion that John will stay. The dialog
(3) Won't John stay?
No, he will stay.
however, is ill-formed. This means that "no" cannot stand for "it is
not the case that". Similarly, the dialog
(4) Won't John stay?
Yes, he won't stay.
4 FERENC KIEFER
too, is deviant, which means that "yes" cannot stand for "it is the case
that" .
The above observations show quite clearly that "yes" and "no"
cannot be considered to be reduced (elliptical) direct answers.
The main problem, however, is that none of the notions of direct
answer as defined in the various logical approaches is satisfactory.
Notice that the intuition on which the epistemic-imperative approach is
based is that answers must be informative. Unfortunately, however, the
notion of the informativeness of an answer has not as yet been
explicated within this framework. Consider, for example, the question
Who lives in Budapest? It would be quite absurd to interpret this
question as asking for the enumeration of all of the about two million
inhabitants of Budapest. Though for every person x who lives in
Budapest x lives in Budapest would constitute a true answer to the
above question, it seems completely pointless to identify the set of such
answers with the meaning of the question Who lives in Budapest?
Similarly, for every person x, x lives in Budapest is a possible answer.
But again it would be pointless to identify the meaning of said question
with the set of all possible answers. What one needs, among other
things, is, of course, a contextually restricted notion of true answer or
possible answer. Similar considerations hold for the categorial ap
proach to the semantics of questions as well.
Or, to take another example, let us assume that somebody asks the
question Where is the Elffel Tower? in Paris. The Elffel Tower is in
Paris counts both as possible and true answer. Nevertheless its informa
tiveness is zero. In the epistemic-imperative approach the interpretation
"Bring it about that I know where the Eiffel Tower is" does not say
anything about which answer satisfies the question, that is, when do I
know where the Eiffel Tower is. What seems to be important, then, is
to have a notion of "pragmatically significant answer". It is worth
while noting that though questions indicate knowledge-desiderata, "the
answers need not necessarily eliminate those desiderata in the sense that
the questioner then knows the particular information after the answer
has been given; often it is already sufficient for him to have some basis
for an assumption, supposition, hypothesis, etc. The amount of know
ledge that will be sufficient for him in each case depends upon what
purposes he has and upon what he already knows." (Grewendorf, this
volume) In other words, the analysis of questions must be able to
express degrees of knowledge and not only complete knowledge.
Yet another problem arises if one considers questions such as Who is
INTRODUCTION 5
Sylvia? In order to provide an informative answer to this question the
knowledge-situation of the questioner has to be taken into account. An
answer such as John's wife may be quite adequate, in other cases,
however, the questioner may use the above question to ask for
information about Sylvia's past, abput her character, etc. This brings
out a further point. The informativeness of the question may depend on
the speaker's purposes or projects. Maybe, this aspect of questions
becomes even more apparent with the question Where is the Eillel
Tower? asked in Paris. Under normal circumstances, the speaker's
purpose may be assumed to be getting to the Eiffel Tower. Therefore,
to simply locate the Eiffel Tower would not be sufficiently informative
and helpful. But an answer in which the questioner is told how to get to
the Eiffel Tower is certainly both informative and helpful.
An adequate account of answers has thus to take into account at least
the following aspects of questions: (i) the speaker's purposes ("teleolo
gical relativity"), (ii) the speaker's state of knowledge at the time the
question is asked and (iii) the relativeness in the elimination of
knowledge desiderata. (Cf. Grewendorf, this volume).
An adequate answer concept has also to take into consideration cases
when the speaker asks the wrong question. He may, for example, have
incorrect presuppositions about certain states of affairs. Let us, for
example, assume that John is a bachelor but he has a girl friend.
Consider now the following question: What is John's wife like? By
answering this question with John is not married the answerer corrects
the questioner's wrong presupposition about John. However, he may
also answer with You mean John's girl friend. She is quite O.K., etc. By
taking into consideration the speaker's purposes and his state of
knowledge, even wrongly put questions can be answered properly.
Sometimes it may not be clear what the speaker's purposes are. In
such cases the answerer may provide several responses, among other
things, "suggestive indirect responses". (CL Joshi, this volume).
The general moral to be drawn from the above considerations is that
answer hood is essentially a pragmatic notion. In traditional semantic
systems there is no way to tell when a question is answered. The only
thing one can say semantically about answers is which, for each
question, are the contextually independent possible answers.
As we saw above, the clarification of the contextual restrictions is a
very important line of research. Its importance is not exhausted by its
theoretical value. Practical applications (for example, question answer
ing systems), too, presuppose an adequate account of questions and
answers.
