Victor Sadler
WORKING
WITH
ANALOGICAL SEMANTICS:
Disambiguation Techniques in DLT
1989
FORIS PUBLICATIONS
(Distributed
Language Translation 5)
[copyright
Mouton de Gruyter]
Table of Contents
Acknowledgements
… 8
Introduction … 9
Part I: Prototype R&D
Chapter 1. The field: Types of ambiguity relevant to machine translation … 15
1.1 Types and terms …. 17
1.1.1
Lexical
ambiguity … 18
1.1.2
Relational
ambiguity … 19
1.2 The scale of difficulty … 25
Chapter 2. The background: Development of the prototype architecture … 27
2.1
Dumb syntax, smart
semantics … 30
2.2
The knowledge sources …
33
2.2.1
Potential sources … 33
2.2.2
Knowledge sources in
the prototype … 36
Chapter 3. The theory: Assessing plausibility … 39
3.1
What
constitutes plausibility? … 40
3.2
Methods
of assessing plausibility … 41
3.2.1
The
conventional approach: features and primitives … 41
3.2.2
The DLT prototype:
collecting the evidence … 43
3.2.3
The first DLT prototype:
making meaning explicit … 46
3.2.4
The
second DLT prototype: leaving meaning implicit … 50
Chapter 4. The techniques: Reasoning by analogy … 53
4.1
The
word match … 55
4.2
Disambiguating
the source language … 59
4.2.1
Lexical choice: the
word pair match … 59
4.2.2
The Y match … 61
4.2.3
The
X match … 62
4.2.4
Combining the X and Y
matches … 64
4.2.5
Combining
word pair matches … 64
4.2.6
Resolving
relational ambiguities … 66
4.2.7
The
disambiguation dialogue … 68
4.3 Disambiguating the intermediate language … 71
4.3.1
Contextual
cues in the bilingual dictionary … 72
4.3.2
Word match and
expectancy match … 74
4.3.3
Method of the
expectancy match … 76
4.3.4
Combining
the match scores … 77
4.3.5
Functional
disambiguation … 78
Chapter 5. The evaluation: Tests and limitations … 81
5.1 Some tests of SWESIL … 82
5.1.1
Testing
the word match function … 82
5.1.2
Testing
the word pair match function … 86
5.1.3
The
Meijby Test … 89
5.1.4
Applications
for referential disambiguation … 98
5.2 The limitations of SWESIL … 99
5.2.1
Strategic
problems … 99
5.2.2
Limitations
on existing functions … 102
5.2.3
Adding
new functions … 104
Part II: Design for a production system
Chapter 6. The Bilingual Knowledge Bank: An integrated knowledge source for machine translation … 109
6.1 Rationale for a BKB … 110
6.1.1
Objectivity:
the corpus as primary knowledge resource
… 110
6.1.2
Dictionary
building: the need for a bilingual corpus
… 111
6.1.3
Reversibility:
the use of bilingual context … 112
6.1.4
Consistency:
discarding the LKB … 114
6.1.5
Quantity:
structuring the corpus … 116
6.1.6
Scope:
increasing the breadth of knowledge … 119
6.1.7
Specificity:
processing encyclopaedic knowledge …
122
6.1.8
Sensitivity:
distinguishing word senses … 124
6.1.9
Productivity:
towards full alignment … 126
6.1.10
Dynamicity:
updating the knowledge sources … 131
6.1.11
Probability:
relativising the frequencies … 132
6.1.12
The
conclusion: the need for an on-line corpus
… 132
6.1.13
Comparison
with other research … 133
6.2 Constructing the BKB … 137
6.2.1
Structural
disambiguation … 137
6.2.2
Identifying
translation units … 139
6.2.3
Identifying
referents … 140
6.3 Advantages and spin-offs of the BKB approach … 143
6.3.1
Basic
advantages … 143
6.3.2 The spin-offs … 145
6.3.3 Possible objections … 146
Chapter 7. Disambiguation with a BKB: Something old and something new, something borrowed... 149
7.1 Towards a new process architecture … 153
7.1.1
Selecting
the translation units … 155
7.1.2
Challenging
the selections … 156
7.1.3
Backtracking
… 157
7.2 Examples of (simulated) BKB-based disambiguation … 158
7.2.1
An
example of lexical disambiguation … 159
7.2.2
Choosing
between TL synonyms … 182
7.2.3
Structural
disambiguation … 186
7.2.4
Functional
disambiguation … 188
7.2.5
Referential
disambiguation … 190
7.3 Principles and techniques …. 193
7.3.1
TU selection by the Metataxor … 193
7.3.2
Semantic
coherence and the Examiner … 195
7.3.3
Evaluating
referential relations … 198
7.3.4
Evaluating
functional relations … 198
7.3.5
Backtracking and
semantic feedback … 200
7.4 A new look at the disambiguation dialogue … 202
7.4.1
Structural
ambiguity … 203
7.4.2
Referential
ambiguity … 204
7.4.3
Functional ambiguity … 204
7.4.4 Lexical ambiguity … 205
Chapter 8. Towards intelligent disambiguation: Inferencing over the BKB … 207
8.1 Inferring indirect referential relations … 209
8.1.1
Inference based on
explicit references … 209
8.1.2
Inference in the
absence of explicit references … 212
8.2
Recognizing
contradictions and inconsistencies … 218
8.3
Exploring
deeper implications … 223
8.4
The BKB as a basis for
inference procedures … 227
8.4.1
Discovering
inference rules … 227
8.4.2
Applying inference
rules … 229
8.4.3
The
knowledge representation … 230
Chapter 9. Spin-off: BKBs, MKBs and other animals... 235
9.1
Other
translation environments … 236
9.2 Monolingual knowledge banks … 241
9.3
Database
applications … 243
In
conclusion … 246
References … 247
Index … 252