Robin Cooper:
Information in the Early Stages of Language Acquisition
In the early stages of language acquisition children seem to use single
words or a small number of words to describe the kind of situations that
adults would describe with complete sentences. We shall sketch a theory
of information states and communication which will account for the fact
that children can use short utterances to report complex situations they
perceive---or at least suggest how they might appear to be doing so to
an adult. We shall suggest that a theory of information states and
communication can give a more explanatory account of early language
acquisition than formal semantics and can provide a theoretical
foundation for the claim in the psycholinguistic literature that
``semantics'' is central to the genesis of language in children.
Furthermore we shall suggest that an examination of the restricted
language used by children and the perception of their utterances by
adults can provide telling arguments for the situated nature of human
language processing.
(April 1990; 11 pages)
Ref. No: HCRC/RP-2 Price: UKL 0.70
Jon Oberlander and Peter Dayan:
Altered States and Virtual Beliefs
Functionalism avoids a potentially fatal infinite regress by realising
the low level phenomena of mind in mere Turing machines rather than via
undischarged homunculae. Adopting a narrow, logical view of such
mechanisms has led to two sorts of problems: exponentially intractable
models of human inferential competence; and a wide divergence between
the supposed competence and observable human performance. These
problems have produced a retreat to instrumentalism about folk
psychological concepts. We argue that abandoning hope in this way is
premature. The problems arise from two quarters: an impoverished notion
of competence models that divorce them too far from performance models;
and too narrow a view of possible functional mechanisms. We explore the
consequences of retaining a traditional view of inference, while
adopting a new mechanism for memory. We motivate the latter by
developing a seemingly unnatural picture of von Neumann machines, taking
their finite memory seriously. Together, the two repairs suffice to
make instrumentalism avoidable.
(April 1990; 10 pages)
Ref. No: HCRC/RP-3 Price: UKL 0.70
Jerry Seligman:
Perspectives in Situation Theory
Situation Theory supplements the logician's diet of individuals,
properties and propositions with a number of new metaphysical
categories. Amongst these are situations, facts (or infons) and
constraints. In this paper we add a new one (perspectives) to
capture the different ways situations are classified by facts they
support and the constraints that hold in them. Importantly, there are
many perspectives on the same situation.
Perspective can be used to explain the `background conditions' appealed
to in situation theoretic accounts of conditionals and also account for
differing intuitions about the flow of information, corresponding to
`logical' and `informational theoretical' (Dretskian) approaches. In
the final section we provide a construction of some of the old
metaphysical categories (individuals and properties) from perspectives
and certain maps between perspectives called shifts. This offers both a
novel approach to characterising individuation and {\em predication and
the possibility of a more parsimonious metaphysics.
(April 1990; 39 pages)
Ref. No: HCRC/RP-4 Price: UKL 1.50
Judy Delin:
Accounting for Cleft Constructions in Discourse: A Multi-Layered
Approach
Existing accounts of why cleft constructions are used in
discourse---such as those that claim that clefts serve to signal
`focus', or that clefts indicate the position of information of a
particular discourse status---are demonstrated to be inadequate when
analysed in the light of a corpus of naturally-occurring data. This
paper points out the problems with some prominent claims about clefts,
and presents an alternative account, suggesting that the decision to
use clefts is based on a combination of factors at the levels of
syntax, semantics and pragmatics.
(April 1990; 33 pages)
Ref. No: HCRC/RP-5 Price: UKL 1.30
Keith Stenning:
Modelling Memory for Models
We contrast two theoretical interpretations of mental models.
Johnson-Laird and his associates
(eg. Johnson-Laird \& Steedman 1978, Johnson-Laird 1983)
interpret models as a medium of mental representation.
Alternatively, models may be treated as abstract objects
which are important because they specify what is represented.
This paper takes the second view of
mental models and shows how a theory of distributed representation of
binding in memory, elaborated elsewhere (Stenning, Shepherd \& Levy
1988, Stenning \& Levy 1988 , explains why people adopt distinctive
reasoning strategies.
(May 1990; 15 pages)
Ref. No: HCRC/RP-6 Price: UKL 1.00
Alex Lascarides:
The Progressive and the Imperfective Paradox
Formal semantics constitutes the framework of the research presented
here, and the aim is to provide a solution to the imperfective paradox;
i.e. explain why ``Max was running'' entails ``Max ran'', but ``Max
was running home'' does not entail ``Max ran home''. This paper is
divided into two parts. In Part I we evaluate what I will call the
Eventual Outcome Strategy for solving the imperfective paradox.
This strategy is commonly used (Dowty 1979, Hinrichs 1983, Cooper
1985), and is highly intuitively motivated. I will show, however,
that the formulations of the intuitions give rise to conflicts and
tensions when it comes to explaining the natural language data. In
Part II we offer a new approach to tackle the imperfective paradox
that overcomes the problems with the Eventual Outcome Strategy.
(June 1990; 38 pages)
Ref. No: HCRC/RP-7 Price: UKL 1.40
Alex Lascarides:
Knowledge, Causality and Temporal Representation
In this paper, a formal semantic framework is developed in order to
account for the temporal semantics of text. The theory is able to
represent and reason about both semantic issues, which are independent
of world knowledge ({\sc wk), and pragmatic issues, which are not,
within a single logical framework. The theory will allow a text's
semantic entailments to differ from its pragmatic ones, even though
they are all derived within the same logic. I demonstrate that this
feature of the theory gives rise to solutions to several puzzles
concerning the temporal structure of text.
(June 1990; 39 pages)
Ref. No: HCRC/RP-8 Price: UKL 1.50
Keith Stenning:
What are We to Make of Computers, and Computers to Make of Us?
Reflections on Winograd and Flores' Understanding Computers and
Cognition
Winograd and Flores' `Understanding Computers and Cognition' proposes
that the rationalist tradition in AI must be replaced by a hermeneutic
approach. Associating the rationalist tradition with the goal of
building a human mind, the authors propose that a hermeneutic approach
must adopt the goal of constructing prostheses which magnify the human
mind.
This paper argues that what AI needs is not so much a hermeneutic
approach as a better appreciation of biology and psychology. These
disciplines are responsible for what we know of organisms adapted to
environments, and the relationship between knowledge and context. This
point of view is illustrated by appeal the distinctive characteristics
of human episodic memory.
(August 1990; 16 pages)
Ref. No: HCRC/RP-9 \sellingprice{pounds 1.00
Matthew W. Crocker:
Incrementality and Modularity in a Principle-Based Model of
Sentence Processing
Central to the ``principles and parameters'' paradigm of modern
transformational grammar is a modular set of axiomatic principles
which are stated in terms of several distinct representational forms;
namely phrase structure, chains, coindexation, and thematic structure.
In previous research, we have hypothesized the existence of four
distince processing modules; one for each informational aspect of the
grammar. The modules are intended to act concurrently, with a
limited flow of communication between them.
This paper describes a ``deductive'' implementation of the processing
model, in which each processing module is a specialised
meta-interpreter over the relevant components of the grammar.
Within this framework, we will show how processing strategies can be
implemented simply as specialised `selection' rules within the
individual meta-interpreters. In addition, the four processors are
``coroutined'' so as to model the concurrency intended by the theory
of processing.
(September 1990; 22 pages)
Ref. No: HCRC/RP-10 Price: UKL 1.10
HCRC Research Overview 1990
(November 1990; 117 pages)
Ref. No: HCRC/RP-12 Price: UKL 0.60
Robin Cooper:
Three Lectures on Situation Theoretic Grammar
This report presents extensive notes for three lectures on Situation
Theoretic Grammar that were prepared for the APPIA Advanced School on
Natural Language Processing, which took place in Guarda, Portugal in
October 1990.
Topics covered include motivation for the situation theoretic approach
to natural language processing, infons, parametric objects,
environments, generalised quantifiers and quantifier scope.
(November 1990; 37 pages)
Ref. No: HCRC/RP-13 Price: UKL 1.40
Judith Ramsey \& Keith Oatley:
Designing Minimal Models from Scratch
We designed from scratch a minimal manual of the kind proposed by
Caroll (1990) for Unix e-mail, using a set of six user measurement
instruments in the different phases of iterative design and testing.
The design process involved acquiring from a set of experts
information about e-mail use that would be helpful to novices, and
acquiring from novices information that guided subsequent versions of
the manual. The seventh version of the minimal manual was tested
against a commercial manual, in a comparative performance experiment
with 30 naive subjects. It had approximately 13\% of the pages of the
commercial manual; it resulted in 30\% faster learning and more
effective use of the e-mail system overall, and significantly better
performance on individual subtasks; including the recovering from
errors. Significantly more users were satisfied with it than the
conventional manual. A serendipitous finding from the performance
experiment was that males made more attempts at error recovery than
females, but were not more successful in recovering from errors.
Carroll's general principles of manual design for minimal manuals were
found to be a good basis for design, and we suggest these guidelines
are suitable for the design of such manuals from scratch.
(November 1990; 41 pages)
Ref. No: HCRC/RP-14 Price: UKL 1.60