E1AR0002@SMUVM1.BITNET (11/04/86)
TECHNICAL NOTE: 151\hfill PRICE: \$20.00\\[0.01in]
\noindent TITLE: THE REPRESENTATION AND USE OF FOCUS IN DIALOGUE\\
AUTHOR: BARBARA J. GROSZ\\
DATE: JULY 1977\\[0.01in]
ABSTRACT: This report develops a representation of focus of
attention that circumscribes discourse contexts within a general
representation of knowledge. Focus of attention is essential to any
comprehension process because what and how a person understands is
strongly influenced by where his attention is directed at a given
moment. To formalize the notion of focus, the need for and the use of
focus mechanisms are considered from the standpoint of building a
computer system that can participate in a natural language dialogue
with a user. Two ranges of focus, global and immediate, are
investigated, and representations for incorporating them in a computer
system as developed.
The global focus in which an utterance is interpreted is
determined by the total discourse and situational setting of the
utterance. It influences what is talked about, how different concepts
are introduced, and how concepts are referenced. To encode global
focus computationally, a representation is developed that highlights
those items that are relevant at a given place in a dialogue. The
underlying knowledge representation is segmented into subunits, called
focus spaces, that contain those items that are in the focus of
attention of a dialogue participant during a particular part of the
dialogue.
Mechanisms are required for updating the focus representation,
because, as a dialogue progresses, the objects and actions that are
relevant to the conversation, and therefore in the participants' focus
of attention, change. Procedures are described for deciding when and
how to shift focus in task-oriented dialogues, i.e., in dialogues in
which the participants are cooperating in a shared task. These
procedures are guided by a representation of the task being performed.
The ability to represent focus of attention in a language understanding
system results in a new approach to an important problem in
discourse comprehension--the identification of the referents of
definite noun phrases. Procedures for identifying referents are
developed that take discourse structure into account and use the
distinction between highlighted items and those that are not
highlighted to constrain the search for the referent of a definite
noun phrase.
Interpretation of an utterance also depends on the immediate
focus established by the linguistic form of the preceding utterance.
The interpretation of elliptical sentence fragments illustrates the
effect of immediate focus. Procedures that interpret elliptical
sentence fragments are developed. The use of a representation that
superimposes syntactic information about an utterance on the
interpretation of the underlying meaning of that utterance to minimize
the processing required to expand a fragment into a complete sentence.\\
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TECHNICAL NOTE: 152\hfill PRICE: \$10.00\\[-0.15in]
\begin{tabbing}
\noindent TITLE: DEVELOPING A NATURAL LANGUAGE INTERFACE TO COMPLEX DATA\\
AUTHORS: \= GARY G. HENDRIX, EARL D. SACERDOTI, DANIEL SAGALOWICZ, and\\
\> JONATHAN SLOCUM\\
DATE: AUGUST 1977\\[-0.15in]
\end{tabbing}
ABSTRACT: This paper describes aspects of an intelligence
interface that provides natural language access to a large body of
data distributed over a computer network. The overall system
architecture is presented, showing how a user is buffered from the
actual data base management systems (DBMSs) by three layers of
insulating components. These layers operate in series to convert
natural language queries into calls to DBMSs at remote sites.
Attention is then focused on the first of the insulating components,
the natural language system. A pragmatic approach to language access
that has proved useful for building interfaces to data bases is
described and illustrated by examples. Special language features that
increase system usability, such as spelling correction, processing of
incomplete inputs, and run-time system personalization, are also
discussed.\\
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TECHNICAL NOTE: 154\hfill PRICE: \$15.00\\[0.01in]
\noindent TITLE: THE LOGIC OF COMPUTER PROGRAMMING\\
AUTHORS: RICHARD WALDINGER and ZOHAR MANNA\\
DATE: AUGUST 1977\\[0.01in]
ABSTRACT: Techniques derived from mathematical logic promise to
provide an alternative to the conventional methodology for
constructing, debugging, and optimizing computer programs. Ultimately, these
techniques are intended to lead to the automation of many of the
facets of the programming process.
This paper provides a unified tutorial exposition of the logical
techniques, illustrating each with examples. The strengths and
limitations of each technique as a practical programming aid are
assessed and attempts to implement these methods in experimental
systems are discussed.\\
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TECHNICAL NOTE: 155\hfill PRICE: \$10.00\\[-0.15in]
\begin{tabbing}
\noindent TITLE: \= PROSPECTOR--A COMPUTER BASED CONSULTATION SYSTEM FOR \\
\> MINERAL EXPLORATION\\
AUTHORS: PETER E. HART and RICHARD O. DUDA\\
DATE: OCTOBER 1977\\[-0.15in]
\end{tabbing}
ABSTRACT: This paper reviews the principles and status of
Prospector, a computer-based consultation program for mineral
exploration. The mechanisms for representing ore deposit models by
networks of inference rules are described, and the overall approach is
compared to alternative decision making methodologies.\\
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TECHNICAL NOTE: 156\hfill PRICE: \$15.00\\[0.01in]
\noindent TITLE: SYNTHESIS: DREAMS == PROGRAMS\\
AUTHORS: RICHARD WALDINGER and ZOHAR MANNA\\
DATE: NOVEMBER 1977\\[0.01in]
ABSTRACT: Deductive techniques are presented for deriving
programs systematically from given specifications. The specifications
express the purpose of the desired program without giving any hint of
the algorithm to be employed. The basic approach is to transform the
specifications repeatedly according to certain rules, until a
satisfactory program is produced. These techniques have been
incorporated in a running program-synthesis system, called DEDALUS.
Many of the transformation rules represent knowledge about the
program's subject domain (e.g., numbers, lists, sets); some represent
the meaning of the constructs of the specification language and the
target programming language; and a few rules represent basic
programming principles. Two of these principles, the conditional-formation
rule and the recursion-formation rule, account for the
introduction of conditional expressions and of recursive calls into
the synthesized program. The termination of the programs is ensured
as new recursive calls are formed.
Two extensions of the recursion-formation rule are discussed; a
procedure-formation rule, which admits the introduction of auxiliary
subroutines in the course of the synthesis process, and a
generalization rule, which causes the specifications to be altered to
represent a more general problem that is nevertheless easier to solve. Special
techniques are introduced for the formation of programs with side
effects.
The techniques of this paper are illustrated with a sequence of
examples of increasing complexity; programs are constructed for list
processing, numerical calculation, and array computation.
The methods of program synthesis can be applied to various
aspects of programming methodology--program transformation, data
abstraction, program modification, and structured programming.
The DEDALUS system accepts specifications expressed in a
high-level language, including set notation, logical quantification,
and a rich vocabulary drawn from a variety of subject domains. The
system attempts to transform the specifications into a recursive,
LISP-like target program. Over one hundred rules have been
implemented, each expressed as a small program in a QLISP language.\\
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TECHNICAL NOTE: 157\hfill PRICE: \$10.00\\[0.01in]
\noindent TITLE: RECOVERING INTRINSIC SCENE CHARACTERISTICS FROM IMAGES\\
AUTHORS: HARRY G. BARROW and J. MARTIN TENENBAUM\\
DATE: APRIL 1978\\[0.01in]
ABSTRACT: We suggest that an appropriate role of early visual
processing is to describe a scene in terms of intrinsic (vertical)
characteristics--such as range, orientation, reflectance, and incident
illumination--of the surface element visible at each point in the
image. Support for this idea comes from three sources: the obvious
utility of intrinsic characteristics for higher-level scene analysis;
the apparent ability of humans to determine these characteristics,
regardless of viewing conditions or familiarity with the scene; and a
theoretical argument that such a description is obtainable, by a
noncognitive and nonpurposive process, at least, for simple scene
domains. The central problem in recovering intrinsic value encodes
all the characteristics of the corresponding scene point. Recovery
depends on exploiting constraints, derived from assumptions about the
nature of the scene and the physics of the imaging process.\\
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TECHNICAL NOTE: 158\hfill PRICE: \$10.00\\[0.01in]
\noindent TITLE: ROAD TRACKING AND ANOMALY DETECTION IN AERIAL IMAGERY\\
AUTHOR: LYNN H. QUAM\\
DATE: MARCH 1979\\[0.01in]
ABSTRACT: This report describes a new procedure for tracking road
segments and finding potential vehicles in imagery of approximately 1
to 3 feet per pixel ground resolution. This work is part of a larger
effort by SRI International to construct an image understanding system
for monitoring roads in aerial imagery.\\
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TECHNICAL NOTE: 163R\hfill PRICE: \$12.00\\[0.01in]
\noindent TITLE: A LADDER USER'S GUIDE (REVISED)\\
AUTHORS: EARL D. SACERDOTI and DANIEL SAGALOWICZ\\
DATE: MARCH 1980\\[0.01in]
ABSTRACT: LADDER (Language Access to Distributed Data with Error
Recovery) is a computer system designed to provide answers to
questions posed at the terminal in a subset of natural language
regarding a distributed data base of naval command and control
information. The system accepts a fairly wide range of
naturalf-language questions about the data. For each question LADDER
plans a sequence of appropriate queries to the data base management
system, determines on which machine the queries are to be processed,
establishes links to those machines over the Arpanet, monitors the
processing of the queries and recovers from certain errors in
execution, and prepares a relevant answer to the original question.
The user's guide is intended for the person who knows how to log in to
the host operating system, as well as how to enter and edit a line of
text. It does not explain how LADDER works, but rather how to use it
on a demonstration basis.\\
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TECHNICAL NOTE: 164\hfill PRICE: \$15.00\\[0.01in]
\noindent TITLE: ENCODING KNOWLEDGE IN PARTITIONED NETWORKS\\
AUTHOR: GARY G. HENDRIX\\
DATE: JUNE 1978\\[0.01in]
ABSTRACT: This paper discusses network notations for encoding a
number of different kinds of knowledge, including taxonomic
information; general statements involving quantification; information
about processes and procedures; the delineation of local contexts,
beliefs, and wishes; and the relationships between syntactic units and
their interpretations.
Many of the encodings appeal to the concept of network
partitioning, in which a large net is partitioned into subnets and
higher-order relationships among the subnets are defined.
Procedural mechanisms for constructing and using the various
network formalisms are discussed as equal partners with the
declarative structures.\\
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TECHNICAL NOTE: 165\hfill PRICE: \$10.00\\[0.01in]
\noindent TITLE: INVESTIGATING THE PROCESS OF NATURAL LANGUAGE COMMUNICATION\\
AUTHOR: ANN E. ROBINSON\\
DATE: JUNE 1978\\[0.01in]
ABSTRACT: This paper provides an overview of an ongoing research
program on natural language communications, indicating its status as
of June 1978, and its short term goals. This research seeks to
identify and computationally formalize the knowledge and processes
needed for participation in natural language dialogs about ongoing
tasks. The paper describes (1) the knowledge embodied in an existing
system that interprets utterances in such dialogs, (2) the formalisms
developed for encoding this knowledge, and (3) the framework in which
the knowledge is combined and coordinated during the interpretation
process. The paper also indicates anticipated extensions that will
lead to refinements of interpretations. These extensions include the
concept of modality, the use of the focus and goals of the dialog in
the identification of the referents of pronouns, and the use of
knowledge about the goals of the other dialog participants in the
interpretation of utterances.\\
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TECHNICAL NOTE: 168\hfill PRICE: \$10.00\\[0.01in]
\noindent TITLE: COHERENCE AND COREFERENCE\\
AUTHOR: JERRY R. HOBBS\\
DATE: AUGUST 1978\\[0.01in]
ABSTRACT: Coherence in conversations and in texts can be
partially characterized by a set of coherence relations, motivated
ultimately by the speaker's or writer's need to be understood. In
this paper, formal definitions are given for several coherence
relations, based on the operations of an inference system; that is,
the relations between successive portions of a discourse are
characterized in terms of the inferences that can be drawn from each.
In analyzing a discourse, it is frequently the case that we would
recognize it as coherent, in that it would satisfy the formal
definition of some coherence relation, if only we could assume certain
noun phrases to be coreferential. In such cases, we will simply
assume the identity of the entities referred to, in what might be
called a petty conversational implicature," thereby solving the
coherence and coreference problems simultaneously. Three examples of
different kinds of reference problems are presented. In each, it is
shown how the coherence of the discourse are solved, almost as a
by-product, by means of these petty conversational implicatures.\\
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TECHNICAL NOTE: 169\hfill PRICE: \$10.00\\[0.01in]
\noindent TITLE: WHY ASK?\\
AUTHORS: JERRY R. HOBBS and JANE J. ROBINSON\\
DATE: OCTOBER 1978\\[0.01in]
ABSTRACT: In this paper, we address the problem, What makes an
answer appropriate?" We do so by investigating indirect answers to
questions in task-oriented dialogues. Three cases are distinguished:
(1) The response, though indirect, answers the question asked; (2) the
response denies a presupposition of the question; and (3) the response
answers to higher goals the questioner was trying to achieve.
Detailed analysis shows the need for knowledge about the task, the
role of the participants, and communication goals, in the construction
of appropriate answers. We conclude with a preliminary formulation of
the appropriateness of an answer in terms of the goals of the
questioner and the knowledge of the respondent.\\
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TECHNICAL NOTE: 170\hfill PRICE: \$10.00\\[0.01in]
\noindent TITLE: HANDLING COMPLEX QUERIES IN A DISTRIBUTED DATA BASE\\
AUTHOR: ROBERT C. MOORE\\
DATE: OCTOBER 1979\\[0.01in]
ABSTRACT: As part of the continuing development of the LADDER
system [1] [2], we have substantially expanded the capabilities of the
data base access component that serves as the interface between the
natural- language front end of LADDER and the data base management
systems on which the data is actually stored. SODA, the new data base
access component, goes beyond its predecessor IDA [3], in that it
accepts a wider range of queries and accesses multiple DBMSs. This
paper is concerned with the first of these areas, and discusses how
the expressive power of the query language was increased, how these
changes affected query processing in a distributed data base, as well
as what are some limitations of and planned extensions to the current
system.\\
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TECHNICAL NOTE: 171\hfill PRICE: \$10.00\\[0.01in]
\noindent TITLE: NATURAL LANGUAGE ACCESS TO A MELANOMA DATA BASE\\
AUTHORS: MARTIN N. EPSTEIN and DONALD E. WALKER\\
DATE: SEPTEMBER 1978\\[0.01in]
ABSTRACT: This paper describes ongoing research towards
developing a system that will allow physicians personal access to
patient medical data through natural language queries to support both
patient management and clinical research. A prototype system has
been implemented for a small data base on malignant melanoma. The
physician can input queries in English that retrieve specified data
for particular patients or for groups of patients satisfying certain
characteristics, that perform simple calculations, that allow browsing
through the data base, and that assist in identifying relations among
attributes. The system supports dialogue interactions; that is, the
user can follow a line of inquiry to test a particular hypothesis by
entering a sequence of queries that depend on each other. Classes of
questions that can be processed are described and examples using the
system are given.\\
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