13.467, Review: Kempson et al., Dynamic Syntax
LINGUIST List
linguist at linguistlist.org
Wed Feb 20 05:28:38 UTC 2002
LINGUIST List: Vol-13-467. Wed Feb 20 2002. ISSN: 1068-4875.
Subject: 13.467, Review: Kempson et al., Dynamic Syntax
Moderators: Anthony Aristar, Wayne State U.<aristar at linguistlist.org>
Helen Dry, Eastern Michigan U. <hdry at linguistlist.org>
Andrew Carnie, U. of Arizona <carnie at linguistlist.org>
Reviews (reviews at linguistlist.org):
Simin Karimi, U. of Arizona
Terence Langendoen, U. of Arizona
Editors (linguist at linguistlist.org):
Karen Milligan, WSU Naomi Ogasawara, EMU
James Yuells, EMU Marie Klopfenstein, WSU
Michael Appleby, EMU Heather Taylor-Loring, EMU
Ljuba Veselinova, Stockholm U. Richard John Harvey, EMU
Dina Kapetangianni, EMU Renee Galvis, WSU
Karolina Owczarzak, EMU
Software: John Remmers, E. Michigan U. <remmers at emunix.emich.edu>
Gayathri Sriram, E. Michigan U. <gayatri at linguistlist.org>
Home Page: http://linguistlist.org/
The LINGUIST List is funded by Eastern Michigan University, Wayne
State University, and donations from subscribers and publishers.
Editor for this issue: Terence Langendoen <terry at linguistlist.org>
==========================================================================
What follows is another discussion note contributed to our Book
Discussion Forum. We expect these discussions to be informal and
interactive; and the author of the book discussed is cordially invited
to join in.
If you are interested in leading a book discussion, look for books
announced on LINGUIST as "available for discussion." (This means that
the publisher has sent us a review copy.) Then contact
Simin Karimi at simin at linguistlist.org
or Terry Langendoen at terry at linguistlist.org.
Subscribe to Blackwell's LL+ at http://www.linguistlistplus.com/ and
donate 20% of your subscription to LINGUIST! You get 30% off on
Blackwells books, and free shipping and postage!
=================================Directory=================================
1)
Date: Tue, 19 Feb 2002 13:17:43 +0100
From: Simon Musgrave <S.Musgrave at let.leidenuniv.nl>
Subject: review of Kempson, Meyer-Viol & Gabbay, Dynamic Syntax
-------------------------------- Message 1 -------------------------------
Date: Tue, 19 Feb 2002 13:17:43 +0100
From: Simon Musgrave <S.Musgrave at let.leidenuniv.nl>
Subject: review of Kempson, Meyer-Viol & Gabbay, Dynamic Syntax
Kempson, Ruth, Wilfried Meyer-Viol and Dov Gabbay (2000)
Dynamic Syntax: The Flow of Language Understanding. Blackwell
Publishers, xii+348pp, paperback ISBN: 0-631-17613-6, $34.95;
hardback ISBN: 0-631-17612-8.
Simon Musgrave, Spinoza Project: Lexicon & Syntax, Leiden
University
OVERVIEW
This monograph provides an introductory account of an
approach to the syntax of natural language based on
incremental parsing of strings of words in temporal/linear
sequence. There are several crucial elements in this
approach. No syntactic structures of the conventional type
are included in the machinery (but I will suggest below
that they are nevertheless assumed). The output of the
parsing process is not a syntactic representation, but a
formula in a logical language. This does not, however,
constitute the denotation of the string. Instead, the
formula is a representation, perhaps an incomplete one, of
the meaning encoded. Pre-final stages of the parse are
represented as trees, the nodes of which are decorated
with logical formulae, and lexical items are conceived as
the transitions between such trees. Each lexical item in
turn triggers a process of updating the tree. This may
involve the projection of new nodes, changing the formulae
which decorate existing nodes, or both. Underspecification
is integral to the parsing process. At any point,
including the final representation, the logical formula
may include metavariables. The reference of these may be
resolved by later updates or it may be left to pragmatics
to provide appropriate reference (Relevance Theory,
Sperber & Wilson 1995, is assumed by the authors to be a
suitable model of such processes). In addition, pre-final
trees may include nodes whose position in the tree is
unspecified. The authors use these mechanisms to analyse
syntactic problems including relative clauses, wh-
questions and crossover phenomena. The book is addressed
firstly to syntacticians but will also be of interest to
students of formal semantics and computational linguists.
The book assumes rather detailed knowledge of at least
some areas of the syntactic literature, and the formalism
used requires the reader to keep track of complex logical
formulae which include portions in standard first-order
logic as well as statements in a modal tree logic. The
appropriate audience is therefore graduate students and
beyond. It is to the credit of the authors that their
exposition is, for the most part, lucid and readable.
The book consists of a preface, nine chapters, a
bibliography, a general index and an index of symbols. The
first chapter offers an argument for the necessity of the
approach adopted. Chapters 2 and 3 lay out the basics of
the parsing model, with chapter 2 introducing the formal
languages used and chapter 3 describing the mechanisms
assumed. Chapters 4 - 7 present analyses of specific
problems, respectively relative clauses, wh-questions,
crossover phenomena and quantification. Chapter 8 returns
to more general issues and sketches some thoughts about
the design of language implied by the parsing-based
approach. Chapter 9 is a detailed presentation of the
formal apparatus.
Synopsis:
Chapter 1 (Towards a syntactic model of interpretation)
argues for an alternative to what is claimed to be the
dominant paradigm in linguistics: that knowledge of
language as a formal system must be characterised before
it is possible to say anything about how that knowledge is
used. The authors (afterwards KMG) propose what they claim
is a more common-sense view, that knowledge of language
means being able to process strings incrementally in order
to extract (some) meaning from them. The only formal
structure which exists in such a model is the sequence of
partial interpretations which lead to the final
representation. This argument is grounded in a discussion
of the problems of the semantics of pronouns. Well-known
problems preclude a straightforward denotational account
of the meaning of pronouns and similar problems are argued
to apply to definite NPs as well. KMG take this to show
that the meaning communicated in language must be
representational rather than denotational, and that such
representations must inevitably include un- or under-
specified elements. These representations must
underdetermine meaning, but in association with pragmatic
processes, they can provide a context-specific content.
The task of syntax is to model the process of building up
the representation, a propositional formula, which can be
interpreted in context.
Chapter 2 (The General Framework) introduces the formal
apparatus used. The basis of this apparatus is the use of
labelled deductive systems, where deduction is defined for
pairs of labels and formulae. In the current model, each
tree node is decorated with a label-formula pair. The
formulae are statements of a logical form, expressed as
terms in a typed lambda calculus. The labels provide the
information which controls how the formulae can combine
(how the tree is built), and they consist of two types of
information. Firstly, the logical type of the term is a
part of the label. Secondly, information about the
relation of the node to other nodes in the tree is
expressed in the label using the tree modalities of the
Logic of Finite Trees (Blackburn & Meyer-Viol 1995). These
modalities allow a label to refer to daughters of the node
(including a distinction between argument daughter and
function daughter), to the mother of the node and also to
any dominating node or any dominated node. Each node also
is annotated with a set of requirements. These are
expressed using the resources already described. They can
specify the information needed to complete the annotation
of the current node, for example, the root node of every
tree introduced with the initial word of the string is
annotated with a requirement that the node ultimately be
decorated with a formula of type t. Requirements can also
specify restrictions on other nodes, for example a
transitive verb introduces the requirement that its mother
node should have a daughter of type e. Thus requirements
drive the process of building a tree and an
interpretation.
Chapter 3 (The Dynamics of Tree Building) describes the
processes by which trees are constructed. These are of
three types: computational rules, lexical actions and
pragmatic actions. The first type of process does not
change the information content of the tree. Computational
rules are rewrite rules which take either the annotation
of a node or the requirements of a node and use them to
compute additional facts. Lexical actions map one tree
description to another one, adding information. (The
parsing process is strictly monotonic.) Lexical items are
the transitions between one (partial) tree and another and
lexical entries take the form of conditional statements.
If any requirements are associated with the item, they
make up the antecedent of the conditional. If the
condition is met, then the actions associated with the
item are carried out, otherwise the transition is aborted.
Pragmatic actions add information to a tree which is not
contained in the string or is not a result of principles
within the language system. These actions can be
inferences using external information in association with
annotations at a node, or the replacement of metavariables
by more complete terms. Examples of how this process
operates in detail are given for English and for Japanese.
Japanese is chosen because it is verb-final, which means
crucial lexical information is available only late in the
parsing process, and because it is sometimes analysed as
being non-configurational. But in the current model, the
result of the parse must be of the same type: the final
tree is a propositional structure with the combination of
nodes driven solely by the logical types of the leaves and
this must be identical for all languages. The difference
between the two languages is in the degree to which the
pre-final trees have fixed nodes or unspecified nodes,
which equates to a "different load carried by general
rules and the lexicon." (p. 75). In a language such as
English, general rules allow the hearer to infer the
logical type which must annotate some nodes, for example a
NP following a verb will be of type (e > (e > t)). But in
Japanese, this information is provided by lexical items,
case markers, which project requirements as to the
environment which the NP must finally occupy in the tree.
This is very close to the concept of 'constructive case'
used in recent work in Lexical-Functional Grammar
(Nordlinger 1998), a comparison not made by KMG although
this chapter does include a comparison of their approach
with several other current frameworks.
Chapter 4 (Linked Tree Structures) deals with relative
clause constructions and also includes a brief discussion
of genitive constructions. The crucial move which allows
the analysis of relative clauses is to allow one tree to
be linked to another with a formula annotating a node in
one tree being identified with a formula annotating a node
in the other tree. In a language such as English with
head-initial relative clauses, this means that the head
noun is linked to the root node of another tree, and some
node within that tree is required to be annotated with a
copy of the formula which annotates the head. The relation
between the trees is defined as a tree modality; that is,
there is a rule of LINK introduction (more accurately, a
family of rules) which define how information is shared
between the two structures. The interpretation which
results is that of a co-ordination. To quote the example
given on p. 111, the sentence:
John, who I much admire, has left MIT.
is given an interpretation equivalent to:
John has left MIT and I much admire John.
The various possibilities for relative clause
constructions which occur in different languages are
accounted for by variation in the nature of the LINK
relation and its mode of introduction. In languages which
have a relativizer (or several of them), the LINK relation
is projected by these lexical items. In languages which do
not use relativizers, the relation can be introduced
freely, other conditions being met. If a relativizer is
used, it may or may not project the copy of the head node
formula itself: if it does, then the formula annotates an
(initially) unfixed node in the linked tree; if not, a
requirement for the copy is projected and this must be
fulfilled in the linked tree by some anaphoric device,
typically a resumptive pronoun. These mechanisms are
argued to extend naturally to the analysis of head-final
relatives in, for example, Japanese (see further
discussion in the evaluation below) and even to so-called
internally-headed relative clauses. Brief sections of this
chapter also suggest that the LINK relation can be used to
analyse topicalisation structures with resumptive clitics,
and to analyse genitive constructions.
Chapter 5 (Wh questions: a general perspective) extends
the representationalist perspective of the Dynamic Syntax
(DS) approach to the analysis of wh- questions. The
authors argue that there are problems with a denotational
account of wh- items which are very similar to the
problems they identified for anaphora in chapter 1. In
particular, they note that although a standard view is
that wh- items are operators which bind variables, there
are many cases where scope interactions do not fall out as
would be predicted on that account. The DS alternative is
to treat wh- items as projecting a meta-variable which is
a part of the formula annotating the root node of the
final tree. Semantically, the meaning of a question is not
fully specified; only a question and answer pair allows a
complete interpretation. On this basis, there is no
difference between fronted wh- constructions and in situ
wh- constructions: the lexical item projects a meta-
variable which ends up as part of the formula annotating
the root node. The difference between the two
possibilities is that a fronted wh- item has no fixed tree
position when it is parsed, this will only be established
as the tree is developed. The bulk of this chapter is
devoted to a discussion of expletive wh- phenomena and so-
called partial movement:
Was glaubst du, wen Jakob half?
what think you whom Jacob helped
'Who do you think Jacob helped?'
Such structures have been problematic for other frameworks
(e.g. Horvath 1997, Johnson and Lappin 1999), but are handled
in a straightforward fashion in the DS framework. The basic
idea is that the initial wh- item (the wh- expletive) does not
introduce a meta-variable itself. Rather it projects a
requirement for some node following to introduce the meta-
variable. The possibility of additional intermediate
expletives and the various possibilities for the full wh- item
(position in its clause, locality with respect to the nearest
expletive, and whether case-marking affects the full wh- item
or an expletive node) all can be analysed as differences in
the specification of the path between the expletive and the
node which is annotated with the meta-variable. The chapter
closes with a return to the problem of scope in questions,
which is a non-problem in terms of the analyses proposed. The
meta-variable in the logical formula which is the parse of a
wh- question has no scope-taking properties and cannot
interact with any quantifiers in the formula. But when the
meta-variable is substituted by a term in the formula which
represents an answer, then necessarily a choice is made as to
whether it falls within the scope of a quantifier. But this
choice has nothing to do with the wh- item.
Chapter 6 (Crossover Phenomena) considers the well-known
problems of crossover from the DS perspective. Restrictions on
interpretation of strong crossover structures are analysed as
the result of interaction between locality constraints on
pronominal interpretation, and the dynamic process by which
the unfixed node in a relative clause comes to be fixed. The
locality restrictions ensure that the only way the head of a
relative clause and a pronoun within the relative clause can
co-refer is for the unfixed node to be merged with the node
annotated by the pronoun. But this means that there cannot be
a gap within the relative clause, that is, a node within the
relative clause which projects a requirement (in this case,
for a formula of type e), because the unfixed node is no
longer available to merge with it. These considerations do not
apply to weak crossover situations in relative clauses, and
the account also predicts that English crossover structures
with resumptive pronouns should be acceptable. KMG claim that
such pronouns are used frequently in natural data, but note
that judgments are divided and may be influenced by pragmatic
factors. They give the following examples with accompanying
judgments:
?? The man who he agrees he's been overworking is coming on
holiday with us. (p. 201)
My son, who he, even, agrees he's been overworking is coming
on holiday with us. (p. 203)
In my own idiolect, all the examples presented are impossible,
and I therefore have trouble accepting this part of the
analysis. However, following discussion of data from other
languages (Arabic, Hebrew, Dutch), KMG argue that it is
preferable to retain a less restrictive computational system
and rely on (a not yet detailed) pragmatics to rule out some
possibilities and to account for the gradations in judgments.
The discussion of crossover in wh- questions develops this
theme further. If the account given for relative clauses is
correct, then it is predicted that resumptive pronouns will be
possible in wh- crossover structures also, but these are
generally judged as worse by English speakers. KMG
nevertheless continue in their position, providing data that
at least suggests the possibility of resumptive pronouns in
English questions under some pragmatic circumstances. They
also note that cross-linguistic variation in crossover
restrictions cannot be attributed to pragmatic factors, and
show that some of the observed variation at least can be
explained in terms of the difference between weak and strong
pronouns, and differences in the lexical forms in different
languages.
Chapter 7 (Quantification preliminaries) motivates the
decision of KMG to treat noun phrases as being of type e,
rather than as generalized quantifiers (type [[e -> t] -> t])
as in much work following Montague 1974. The discussion also
aims to demonstrate how the interpretations of pronouns which
show quantificational behaviour (bound variable and E-type
effects) arise in the DS model. The initial step in the
argument is to show that the construal of indefinite
determiners has the same character of pragmatic choice as the
construal of pronouns. Specifically, restrictions on the
construal of indefinites are not such as would be expected if
there were a syntactic relation analogous to a long-distance
dependency between the quantifier and the term on which it
depends. The solution proposed is that all noun phrases
include a quantificational element and an optional part of
that element is a scope statement which specifies the scope of
that quantification relative to other quantifications. These
scope statements are collected as the tree is constructed and
are evaluated fully in the formula annotating the root node.
Indefinites have no scope statement, and therefore their
relative scope is open to pragmatic choice in the final
evaluation (cf. the treatment of scope and wh- items in
chapter 5). Bound variable interpretations of pronouns fall
under the cases in which a scope statement is part of the
antecedent term. The evaluation of scope is handled formally
by the use of an epsilon calculus in which quantified terms
are reconstructed without quantifiers but with sufficient
internal structure to allow full evaluation (Hilbert and
Bernays 1939 - the text and the bibliography do not match at
this point, one of only a handful of editing errors I
detected). This has the consequence that E-type
interpretations of pronouns arise naturally under general
principles of term construction. The general point of the
discussion in this chapter is that the idea of
underspecification in a formula, and the interaction of
computational and pragmatic actions which results from this,
can be extended to the realm of quantification with
interesting results.
Chapter 8 (Reflections on Language Design) returns to the
ideas of chapter 1. I give only a brief summary here, as many
of the points covered are discussed in my evaluation below.
The first subsection recapitulates the essential points of the
framework. The second section Underspecification and the
Formal Language Metaphor, sets out the advantageous
consequences of denying a homomorphism between semantic and
syntactic structures and revises the notion of
compositionality to fit the DS framework. Section 3
establishes that a distinction between well-formedness and
acceptability can be made within the framework, despite the
extensive reliance on pragmatics, and section 4 suggests ways
in which cross-linguistic variation can be handled by the
framework. The brief, final section of the chapter touches on
philosophical issues and suggests two consequences flowing
from the DS approach: parsing is a basic property of the
language system, and knowledge of language "is simply the
capacity to construct appropriate decorated structures as
interpretations of stimuli of a particular sort" (p. 267).
Chapter 9 (The Formal Framework) gives full details of the
formal apparatus used elsewhere in the volume, and will not be
further discussed here.
EVALUATION
Before proceeding further, I would like to emphasise that I
consider that this is an important book and that the ideas
presented in it deserve the close attention of syntacticians
and semanticists. Not everything can be covered in a single
book, and the following comments aim to delineate some areas
in which I was left with unanswered questions.
The first of these is the status of rules as a part of the
formalism. Syntactic structure in the conventional sense does
not exist in the DS framework. Indeed if the claim of KMG that
the only structure necessary is the sequence of partial
interpretations, then DS is a way of doing compositional
semantics rather than a way of doing syntax. But the sort of
generalisations which conventional syntax is good at capturing
are also needed in the new approach and their treatment is
disparate. For example, the rule of Introduction (p. 80) allows
the expansion of a requirement at one node to multiple
requirements that can be met at other nodes. In English, this
rule allows the requirement at the root node of a clause for a
formula of type t to be expanded to requirements for formulae
of type e and type e -> t at two additional nodes. This is
treated as a language specific application of a general rule,
and as such looks suspiciously like a phrase structure rule of
the type S -> NP VP. A very different case crops up in the
analysis of relative clauses in Japanese, where certain
sequences of words are taken to define clause boundaries (verb
+ verb, verb + noun). This is handled, in the example
discussed (pp. 135-6), by a disjunction in the lexical entry of
the noun: where the noun follows a verb, it must head a
relative clause, but not elsewhere (of course there are no
statements of this type in the language of DS - the actual
disjunction depends on the requirement projected by the node
which the parsing process is examining). Presumably a similar
disjunction will be necessary in the lexical entries of verbs
to handle the verb + verb sequences. But these disjunctions
appear in the lexical entries of individual lexical items, and
the inference is that, as any noun or verb can occur in such
an environment, such a disjunction is required in the lexical
entry for every noun and every verb. (This might not be as
unwieldy as it seems in the preceding statement. Although KMG
do not mention the possibility, it is easy to see how this
sort of problem could be handled in a lexicon structured into
inheritance hierarchies (Flickinger 1987).) Both cases
discussed above are very naturally described in terms of the
order of elements in surface strings, that is, in syntactic
generalisations. In both the cases mentioned, it seems that
such description is a part of the account given by KMG but its
status within the framework is not the same in each case, and
is not made explicit in either case.
A second issue, discussed by KMG in at least two places (pp. 209-
213, pp. 264-266), is the power of the formal apparatus. DS is
the process of mapping from a language string to a series of
partial trees representing propositional formulae, with
lexical items defined by the transitions between these partial
trees. The propositional formulae are defined in advance
(their form, not their content), and therefore a lexical item
can be the informational difference between any two
propositional formulae. Many such items would clearly be
highly implausible, but they are not excluded from the system
in principle. Similarly, the rule of Introduction discussed in
the previous paragraph can be applied to license any
combination of nodes, provided that the logical types of their
annotating formulae can be combined and reduced to the
annotation of the original node. This also allows for a very
wide range of possibilities. KMG restrict themselves to the
use of only some simple logical types, and this in turn
restricts both the nature of lexical items and the use of the
Introduction rule. But it is not clear to me that this
restriction is intrinsic to the framework, or is a decision
taken by KMG. If the second possibility is correct, then the
framework could be used in an extremely unrestricted way. The
discussions which KMG give on this topic centre on the
question of whether the framework should be restricted or
whether pragmatics can do the work. The answer they choose,
that pragmatics can do a lot of work, is a principled one for
the cases they discuss, but the more general question of what
the framework actually rules out is not answered clearly.
Particularly, the discussions of cross-linguistic variation in
chapters 4-6 and pp. 264-66 are strong in showing that the DS
framework can deal with a wide range of data, but are less
strong on demonstrating what possibilities can be ruled out.
But what we might call "deductive typology", the cataloguing
of what a theory does and does not allow, requires both types
of evidence. (This comment applies rather less to chapter 6,
on wh- questions, than it does to the other two data-based
chapters. The analysis of wh- items, particularly the
discussion of partial movement, is the strongest analysis
presented in the book in my opinion.) This criticism is, at
this point, directed to presentation rather than substance.
For example. the analysis of relative clause structures which
is presented by KMG does rule out some possibilities, as seen
in the discussion of strong-crossover (pp. 196-99). It is easy
to sympathise with the authors and the choices that they must
have had to make as to whether to extend the empirical
coverage of their presentation, or to include more theoretical
discussion. But I would suggest that detailed discussions of
how restrictive or unrestrictive the DS approach really is
should have a high priority in future work. Other rigorous
syntactic theories have not always distinguished themselves in
this regard either, but this only means that the field is open
for a serious competitor to prove itself.
Finally, I would have been delighted to see more discussion of
the problem of production in the book. Again, an introductory
volume cannot cover all aspects of a new approach, but it is
disappointing to see the issue mentioned and dealt with in
only a few sentences. In an approach which is explicitly based
in the processing of language, I would have preferred for the
question not to have been raised at all, rather than to have
been treated in this way: "Production has to be characterised
as in some way parasitic on the process of parsing." (p. 267).
My first impression is that there is no obvious way in which
this program could be carried out using the DS framework. The
parsing process is monotonic, but the actions triggered by
lexical items depend on conditional implication. Therefore
reversing the process is not possible. It may be the case that
when the role of word order generalisations is made clearer, a
production mechanism will be more straightforward. Again, this
is not an area in which other theories necessarily have good
track records, but in addition to the opportunity for staking
a position that this affords, a theory which takes processing
as central should have something concrete to say about
production as another aspect of language processing.
REFERENCES
Flickinger, Daniel (1987) Lexical Rules in the Hierarchical
Lexicon. PhD Dissertation, Stanford University
Hilbert, D. & P. Bernays (1939) Grundlagen der Mathematik
II. Berlin: Julius Springer
Horvath, J. (1997) The status of 'wh-expletives' and the
partial wh-movement construction. Natural Language and
Linguistic Theory 15: 509-572
Johnson, D. and S. Lappin (1999) Local Constraints on
Economy. Stanford CA: CSLI Publications
Montague, R. (1974) The proper treatment of quantification
in ordinary English. In Formal Philosophy: Selected Papers
of Richard Montague, ed. by R. Thomason, pp. 247-270. New
Haven: Yale University Press
Nordlinger, Rachel (1998) Constructive Case. Stanford CA:
CSLI Publications
Sperber, Dan & Deirdre Wilson (1995) Relevance: Cognition
and Communication. Oxford: Blackwell (2nd ed)
ABOUT THE REVIEWER
Simon Musgrave is a post-doctoral researcher at the
University of Leiden. His doctoral thesis is a study of
non-subject arguments in Indonesian, using LFG as the
theoretical framework. He is currently working on a cross-
linguistic database for the Spinoza Project, Lexicon &
Syntax, and is part of the East Indonesia research group
within the project.
ACKNOWLEDGMENT
I am grateful to Crit Cremers for helpful comments on a draft
of this review.
---------------------------------------------------------------------------
If you buy this book please tell the publisher or author
that you saw it reviewed on the LINGUIST list.
---------------------------------------------------------------------------
LINGUIST List: Vol-13-467
More information about the LINGUIST
mailing list