UNIVERSITY OF CALIFORNIA, SAN DIEGO Phonotactic probability in Amharic

185 Pages·2013·6.26 MB·English

UC San Diego
UC San Diego Electronic Theses and Dissertations
Title
Phonotactic probability in Amharic : : a psycholinguistic and computational investigation
Permalink
https://escholarship.org/uc/item/32v7w7gn
Author
Colavin, Rebecca Irene Victoria
Publication Date
2013

Peer reviewed|Thesis/dissertation
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University of California
UNIVERSITY OF CALIFORNIA, SAN DIEGO
Phonotactic probability in Amharic: a psycholinguistic and
computational investigation
A dissertation submitted in partial satisfaction of the
requirements for the degree
Doctor of Philosophy
in
Linguistics
by
Rebecca Irene Victoria Colavin
Committee in charge:
Professor Sharon Rose, Co-Chair
Professor Roger Levy, Co-Chair
Professor Eric Bakovic
Professor Gary Cottrell
Professor Robert Malouf
2013
Copyright
Rebecca Irene Victoria Colavin, 2013
All rights reserved.
The dissertation of Rebecca Irene Victoria Colavin is ap-
proved, and it is acceptable in quality and form for pub-
lication on microfilm and electronically:
Co-Chair
Co-Chair
University of California, San Diego
2013
iii
DEDICATION
To Francis, who always says “be happy”
iv
EPIGRAPH
"With the exception of the 'explosive sounds' represented by p̣, q, ṭ, c,̣̌ ṣ and the
guttural χ (frequently pronounced k by Abyssinians themselves) the pronunciation of
Amharic presents little difficulty to an Englishman".
—Armbruster (1908)
v
TABLE OF CONTENTS
Signature Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Dedication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
Epigraph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi
List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Vita . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
Abstract of the Dissertation . . . . . . . . . . . . . . . . . . . . . . . . . . . xviii
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Phonotactic models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1 Phonotactics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 The generative linguistic tradition . . . . . . . . . . . . . . . . . . . 9
2.3 Experimental evidence . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.4 Accounting for gradient speaker judgements . . . . . . . . . . . . . 12
2.4.1 The Generalized Neighbourhood Model . . . . . . . . . . . . 15
2.4.2 Low-order n-gram models . . . . . . . . . . . . . . . . . . . 16
2.5 Accounting for unattested sequences . . . . . . . . . . . . . . . . . 19
2.5.1 The Hayes and Wilson Maxent Phonotactic learner . . . . . 23
2.5.2 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3 Overview of Amharic morphology and phonotactics . . . . . . . . . . . . 35
3.1 Morphology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.2 The Obligatory Contour Principle . . . . . . . . . . . . . . . . . . . 40
3.3 The Obligatory Contour Principle as applied to place of articulation 45
3.4 Dictionary study . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3.4.1 Consonant inventory . . . . . . . . . . . . . . . . . . . . . . 49
3.4.2 OCP-Place . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.5 Experimental evidence . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
vi
4 Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.1 Simulation I: baseline model . . . . . . . . . . . . . . . . . . . . . . 63
4.1.1 Training data . . . . . . . . . . . . . . . . . . . . . . . . . . 64
4.1.2 Test data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4.1.3 Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
4.1.4 Model evaluation . . . . . . . . . . . . . . . . . . . . . . . . 69
4.1.5 Results and discussion . . . . . . . . . . . . . . . . . . . . . 72
4.2 Simulation II: modified model . . . . . . . . . . . . . . . . . . . . . 79
4.2.1 Results and discussion . . . . . . . . . . . . . . . . . . . . . 82
4.3 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
5 Experiment I: Co-occurrence patterns . . . . . . . . . . . . . . . . . . . . 88
5.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
5.2 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
5.2.1 Novel verb construction . . . . . . . . . . . . . . . . . . . . 90
5.2.2 Presentation . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
5.2.3 Participants . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
5.3 Model predictions for Experiment I . . . . . . . . . . . . . . . . . . 101
5.4 Experimental results . . . . . . . . . . . . . . . . . . . . . . . . . . 104
5.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
5.5.1 Speaker ratings . . . . . . . . . . . . . . . . . . . . . . . . . 108
5.5.2 Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
5.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
6 Experiment II: Segmental irregularities . . . . . . . . . . . . . . . . . . . 115
6.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
6.2 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
6.2.1 Nonce word selection . . . . . . . . . . . . . . . . . . . . . . 121
6.2.2 Presentation and speakers . . . . . . . . . . . . . . . . . . . 122
6.3 Model predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
6.3.1 Part A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
6.3.2 Part B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
6.4 Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . 125
6.4.1 Part A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
6.4.2 Part B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
6.5 General discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
6.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Appendix A: Experimental items I . . . . . . . . . . . . . . . . . . . . . . . 142
Appendix B: Experimental items II . . . . . . . . . . . . . . . . . . . . . . . 150
vii
Appendix C: Word rating screen . . . . . . . . . . . . . . . . . . . . . . . . 155
Appendix D: Experiment instructions . . . . . . . . . . . . . . . . . . . . . . 156
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
viii
LIST OF FIGURES
Figure 2.1: Structure of the (English) word space . . . . . . . . . . . . . . 10
Figure 2.2: Graphical representation of a bigram HMM . . . . . . . . . . . 21
Figure 3.1: Prohibited derivations . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 3.2: Licensed derivations . . . . . . . . . . . . . . . . . . . . . . . . 42
Figure 3.3: OCP gradiency . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Figure 4.1: Log-likelihood of training data . . . . . . . . . . . . . . . . . . 73
Figure 4.2: Correlation between model predictions and speaker judgements 74
Figure 4.3: Speaker predictions and model performance for OCP-Place . . . 74
Figure 4.4: Speakers judgements for LA violations . . . . . . . . . . . . . . 78
Figure 4.5: Automatic model predictions for LA violations . . . . . . . . . 79
Figure 4.6: Log-likelihood of data: simulation II . . . . . . . . . . . . . . . 83
Figure 4.7: Speaker judgment correlation: simulation II . . . . . . . . . . . 84
Figure 4.8: Speaker predictions and model performance for OCP-Place . . . 84
Figure 4.9: Automatic model predictions for LA violations: simulation II . 85
Figure 5.1: Distribution of controls compared to real words . . . . . . . . . 95
Figure 5.2: Selection of nonce forms for the ocp-labial-left edge condition . 97
Figure 5.3: Model predictions for OCP-Place violations . . . . . . . . . . . 102
Figure 5.4: Model predictions for identical consonants . . . . . . . . . . . . 103
Figure 5.5: Model predictions for non-homorganic fricative sequences . . . . 104
Figure 5.6: Speaker ratings for OCP-Place . . . . . . . . . . . . . . . . . . 106
Figure 5.7: Speaker ratings for identical consonants . . . . . . . . . . . . . 107
Figure 5.8: Speaker ratings for non-homorganic fricatives . . . . . . . . . . 107
Figure 5.9: Comparison of speaker ratings and model predictions for OCP-
Placepatterns(homorganic,non-identicalconsonants),rarepat-
terns of identical consonants (ABA and AAB), frequent pat-
terns of identical consonants (ABB) and non-homorganic frica-
tives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Figure 5.10: Comparison of speaker ratings and model predictions . . . . . . 113
Figure 6.1: Model predictions for Part A . . . . . . . . . . . . . . . . . . . 123
Figure 6.2: Model predictions for Part B . . . . . . . . . . . . . . . . . . . 124
Figure 6.3: Model predictions for Part B (by segment) . . . . . . . . . . . . 125
Figure 6.4: Over-represented segment [r] . . . . . . . . . . . . . . . . . . . 126
Figure 6.5: Normally-represented segment [t] . . . . . . . . . . . . . . . . . 128
Figure 6.6: [w] in C and C . . . . . . . . . . . . . . . . . . . . . . . . . . 129
1 2
Figure 6.7: Predictions and ratings for Part A . . . . . . . . . . . . . . . . 130
Figure 6.8: Predictions and ratings for Part A (detail) . . . . . . . . . . . . 131
Figure 6.9: Nonce words with [t] (Part B) . . . . . . . . . . . . . . . . . . . 132
Figure 6.10: Nonce words with [w] . . . . . . . . . . . . . . . . . . . . . . . 133
ix