1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
|
\documentclass{beamer}
\mode<presentation>
{
\usetheme{Boadilla}
\setbeamercovered{transparent}}
\usepackage[english]{babel}
\usepackage{times}
\usepackage{xcolor}
\usepackage{colortbl}
%\usepackage{subfigure}
\usepackage{fontspec}
\usepackage{xunicode}
\usepackage{xltxtra}
\usepackage{booktabs}
\newenvironment{CJK}{\fontspec[Scale=0.9]{PMingLiU}}{}
\newenvironment{Geeza}{\fontspec[Scale=0.9]{Geeza Pro}}{}
%% for tables
\newcommand{\mc}{\multicolumn}
\newcommand{\lab}[1]{\multicolumn{1}{c}{#1}}
\newcommand{\ind}[1]{{\fboxsep1pt\raisebox{-.5ex}{\fbox{{\tiny #1}}}}}
\newcommand{\IND}[1]{{\fboxsep1pt\raisebox{0ex}{\fbox{{\small #1}}}}}
\newcommand\production[2]{\ensuremath{\langle\mbox{#1}, \mbox{#2}\rangle}}
%% markup
\newcommand{\buffer}[1]{{\color{blue}\textbf{#1}}}
\newcommand{\pred}[1]{\code{#1}}
%% colors
\newcommand{\textred}[1]{\alert{#1}}
\newcommand{\textblue}[1]{\buffer{#1}}
\definecolor{tablecolor}{cmyk}{0,0.3,0.3,0}
\newcommand{\keytab}[1]{\mc{1}{>{\columncolor{tablecolor}}d}{#1}}
% rules
\newcommand{\psr}[2]{#1 $\rightarrow \langle $ #2 $\rangle$}
\newenvironment{unpacked_itemize}{
\begin{itemize}
\setlength{\itemsep}{10pt}
\setlength{\parskip}{0pt}
\setlength{\parsep}{0pt}
}{\end{itemize}}
\newcommand{\condon}{\hspace{0pt} | \hspace{1pt}}
\definecolor{darkblue}{rgb}{0,0,0.6}
\newcommand{\blueexample}[1]{\textcolor{darkblue}{\rm #1}}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\newcommand{\ws}{\ensuremath{\vec{w}}}
\newcommand{\pu}{\ensuremath{P_0}}
\newcommand{\bx}{\mathbf{x}}
\newcommand{\bz}{\mathbf{z}}
\newcommand{\bd}{\mathbf{d}}
\newcommand{\by}{\mathbf{y}}
\newcommand\bleu{${B{\scriptstyle LEU}}$}
\title[Models of SCFG Induction]{Models of Synchronous Grammar Induction for SMT}
\author[CLSP Workshop 2010]{
Workshop 2010
%Phil Blunsom$^1$ \and Trevor Cohn$^2$ \and Chris Dyer$^3$ \and Adam Lopez$^4$
}
\institute[Baltimore]{
The Center for Speech and Language Processing \\ Johns Hopkins University
% $^1$University of Oxford\\
% $^2$University of Sheffield\\
% $^3$Carnegie Mellon University\\
% $^4$University of Edinburgh
}
\date[June 21]{June 21, 2010}
%\subject{Unsupervised models of Synchronous Grammar Induction for SMT}
%\pgfdeclareimage[height=1.0cm]{university-logo}{logo}
%\logo{\pgfuseimage{university-logo}}
%\AtBeginSection[]
%{
% \begin{frame}<beamer>{Outline}
% %\tableofcontents[currentsection,currentsubsection]
% \tableofcontents[currentsection]
% \end{frame}
%}
%\beamerdefaultoverlayspecification{<+->}
\begin{document}
\begin{frame}
\titlepage
\end{frame}
%\begin{frame}{Outline}
% \tableofcontents
% You might wish to add the option [pausesections]
%\end{frame}
%\begin{frame}{Outline}
% \tableofcontents
% % You might wish to add the option [pausesections]
%\end{frame}
\begin{frame}[t]{Team members}
\begin{center}
{\bf Senior Members} \\
Phil Blunsom (Oxford)\\
Trevor Cohn (Sheffield)\\
Adam Lopez (Edinburgh/COE)\\
Chris Dyer (CMU)\\
Jonathan Graehl (ISI)\\
\vspace{0.2in}
{\bf Graduate Students} \\
Jan Botha (Oxford) \\
Vladimir Eidelman (Maryland) \\
Ziyuan Wang (JHU) \\
ThuyLinh Nguyen (CMU) \\
\vspace{0.2in}
{\bf Undergraduate Students} \\
Olivia Buzek (Maryland) \\
Desai Chen (CMU) \\
\end{center}
\end{frame}
\begin{frame}[t]{Statistical machine translation}
%\vspace{1.0cm}
\begin{exampleblock}{Urdu $\rightarrow$ English}
\begin{figure}
{\centering \includegraphics[scale=0.55]{urdu.pdf}}
\end{figure}
\vspace{0.10cm}
\end{exampleblock}
\begin{itemize}
\item Statistical machine translation: Learn how to translate from parallel corpora.
\end{itemize}
\end{frame}
\begin{frame}[t]{Statistical machine translation: }
%\vspace{1.0cm}
\begin{exampleblock}{Urdu $\rightarrow$ English}
\begin{figure}
{\centering \includegraphics[scale=0.55]{urdu-ref.pdf}}
\end{figure}
\end{exampleblock}
\begin{itemize}
\item Statistical machine translation: Learn how to translate from parallel corpora
\end{itemize}
\end{frame}
\begin{frame}[t]{Statistical machine translation: Before}
%\vspace{1.0cm}
\begin{exampleblock}{Urdu $\rightarrow$ English}
\begin{figure}
{\centering \includegraphics[scale=0.55]{urdu-bl.pdf}}
\end{figure}
\end{exampleblock}
\begin{itemize}
\item Current state-of-the-art translation models struggle with language pairs which exhibit large differences in structure.
\end{itemize}
\end{frame}
\begin{frame}[t]{Statistical machine translation: After}
%\vspace{1.0cm}
\begin{exampleblock}{Urdu $\rightarrow$ English}
\begin{figure}
{\centering \includegraphics[scale=0.55]{urdu-25hp.pdf}}
\end{figure}
\end{exampleblock}
\begin{itemize}
\item In this workshop we've made some small steps towards better translations for difficult language pairs.
\end{itemize}
\end{frame}
\begin{frame}[t]{Statistical machine translation: limitations}
\vspace{1.0cm}
\begin{exampleblock}{Structural divergence between languages:}
%\vspace{0.3cm}
\begin{table}
\centering
\only<1>{
\begin{tabular}{|l|l|}
\hline
{\bf English} & {\bf Who wrote this letter?} \\
\hline
Arabic & \begin{Geeza}من الذي كتب هذه الرسالة؟\end{Geeza} \\
& \textcolor{gray}{(function-word)} (who) (wrote) (this) (the-letter) \\
\hline
Chinese & \begin{CJK}这封 信 是 谁 写 的 ?\end{CJK} \\
& (this) (letter) (be) (who) (write) (come-from) \textcolor{gray}{(function-word)} \\
\hline
\end{tabular}
}
\only<2>{
\begin{tabular}{|l|l|}
\hline
{\bf English} & {\bf \textcolor{blue}{Who} \textcolor{green}{wrote} \textcolor{red}{this} \textcolor{orange}{letter?}} \\
\hline
Arabic & \begin{Geeza}من الذي كتب هذه الرسالة؟\end{Geeza} \\
& \textcolor{gray}{(function-word)} \textcolor{blue}{(who)} \textcolor{green}{(wrote)} \textcolor{red}{(this)} \textcolor{orange}{(the-letter)} \\
\hline
Chinese & \begin{CJK}这封 信 是 谁 写 的 ?\end{CJK} \\
& (this) (letter) (be) (who) (write) (come-from) \textcolor{gray}{(function-word)} \\
\hline
\end{tabular}
}
\only<3->{
\begin{tabular}{|l|l|}
\hline
{\bf English} & {\bf \textcolor{blue}{Who wrote} \textcolor{red}{this letter}?} \\
\hline
Arabic & \begin{Geeza}من الذي كتب هذه الرسالة؟\end{Geeza} \\
& \textcolor{gray}{(function-word)} (who) (wrote) (this) (the-letter) \\
\hline
Chinese & \begin{CJK}\textcolor{red}{这封 信} \textcolor{blue}{是 谁 写} 的 ?\end{CJK} \\
& \textcolor{red}{(this) (letter)} \textcolor{blue}{(be) (who) (write) (come-from)} \textcolor{gray}{(function-word)} \\
\hline
\end{tabular}
}
\end{table}
\end{exampleblock}
\only<4>{
\begin{itemize}
\item Phrasal translation equivalences \textcolor{green}{(existing models)}
\item {\bf Constituent reordering \textcolor{blue}{(this workshop!)}}
\item Morphology \textcolor{red}{(Next year?)}
\end{itemize}
}
\end{frame}
\begin{frame}[t]{Statistical machine translation: successes}
\begin{center}
\includegraphics[scale=0.35]{GoogleTranslateLanguages.pdf}
\end{center}
\end{frame}
\begin{frame}[t]{Workshop overview}
Input:
\begin{itemize}
% \item Joshua decoder
\item Existing procedures for synchronous grammar extraction
\end{itemize}
\vspace{0.3in}
Output:
\begin{itemize}
\item New unsupervised models for large scale synchronous grammar extraction,
% \item An implementation of this model,
\item A comparison and analysis of the existing and proposed models,
\item Extended decoders (cdec/Joshua) capable of working efficiently with these models.
\end{itemize}
\end{frame}
\begin{frame}[t]{Models of translation}
\begin{exampleblock}{Supervised SCFG: Syntactic Tree-to-String}
\begin{center}
\includegraphics[scale=0.55]{JeNeVeuxPasTravailler-tsg.pdf}
\hspace{0.3in}
\includegraphics[scale=0.55]{JeVeuxTravailler-tsg.pdf}
\end{center}
\end{exampleblock}
\begin{itemize}
\item Strong model of sentence structure.
\item Reliant on a treebank to train the parser.
\end{itemize}
\end{frame}
\begin{frame}[t]{Models of translation}
\begin{block}{Unlabelled SCFG: Hiero}
\begin{center}
\includegraphics[scale=0.55]{JeNeVeuxPasTravailler-Hiero.pdf}
\hspace{0.3in}
\includegraphics[scale=0.55]{JeVeuxTravailler-Hiero.pdf}
\end{center}
\end{block}
\begin{itemize}
\item Only requires the parallel corpus.
\item But weak model of sentence structure.
\end{itemize}
\end{frame}
\begin{frame}
\frametitle{Using syntax in Machine Translation:}
\footnotesize
\begin{block}{Synchronous Context Free Grammar (SCFG)}
\begin{figure}
\begin{align*}
\alert<2>{S} & \alert<2>{\rightarrow \langle X\ind{1},\ X\ind{1} \rangle}
&\quad \alert<3,5>{X} & \alert<3,5>{\rightarrow \langle X\ind{1}\ X\ind{2},\ X\ind{1}\ X\ind{2} \rangle} \\
\alert<7>{X} & \alert<7>{\rightarrow \langle X\ind{1}\ X\ind{2},\ X\ind{2}\ X\ind{1} \rangle} & &\\
\alert<4>{X} & \alert<4>{\rightarrow \langle Sie,\ She \rangle}
&\quad \alert<6>{X} & \alert<6>{\rightarrow \langle will,\ wants\ to \rangle} \\
\alert<8>{X} & \alert<8>{\rightarrow \langle eine\ Tasse\ Kaffee,\ a\ cup\ of\ coffee \rangle}
&\quad \alert<9>{X} & \alert<9>{\rightarrow \langle trinken,\ drink\rangle} \\
\end{align*}
\end{figure}
\end{block}
\begin{exampleblock}{Example Derivation}
%\begin{figure}
%\begin{align*}
\center
\vspace{0.2cm}
\onslide<2->{\alert<2>{$S \Rightarrow \langle X\ind{1},\ X\ind{1}\ \rangle$}} \quad \onslide<3->{\alert<3>{$\Rightarrow \langle X\ind{2}\ X\ind{3},\ X\ind{2}\ X\ind{3} \rangle$ \\}}
\vspace{0.2cm}
\onslide<4->{\alert<4>{$\Rightarrow \langle Sie\ X\ind{3},\ She\ X\ind{3} \rangle$}} \quad \onslide<5->{\alert<5>{$\Rightarrow \langle Sie\ X\ind{4}\ X\ind{5},\ She\ X\ind{4}\ X\ind{5} \rangle$ \\}}
\vspace{0.2cm}
\onslide<6->{\alert<6>{$\Rightarrow \langle Sie\ will\ X\ind{5},\ She\ wants\ to\ X\ind{5} \rangle$ }} \quad \onslide<7->{\alert<7>{$\Rightarrow \langle Sie\ will\ X\ind{6} X\ind{7},\ She\ wants\ to\ X\ind{7} X\ind{6} \rangle$ \\}}
\vspace{0.2cm}
\onslide<8->{\alert<8>{$\Rightarrow \langle Sie\ will\ eine\ Tasse\ Kaffee\ X\ind{7},\ She\ wants\ to\ X\ind{7}\ a\ cup\ of\ coffee\rangle$} \\}
\vspace{0.2cm}
\onslide<9->{\alert<9>{$\Rightarrow \langle Sie\ will\ eine\ Tasse\ Kaffee\ trinken,\ She\ wants\ to\ drink\ a\ cup\ of\ coffee\rangle$}}
\vspace{0.2cm}
%\end{align*}
%\end{figure}
\end{exampleblock}
\end{frame}
\begin{frame}[t]{Models of translation}
\begin{exampleblock}{Phrase extraction:}
\begin{center}
\only<1>{\includegraphics[scale=0.8]{PhraseExtraction6.pdf}\\[1cm]}
\only<2>{\includegraphics[scale=0.8]{PhraseExtraction5.pdf}\\[1cm]}
\only<3>{\includegraphics[scale=0.8]{PhraseExtraction4.pdf}\\[1cm]}
\only<4>{\includegraphics[scale=0.8]{PhraseExtraction3.pdf}\\[1cm]}
\only<5>{\includegraphics[scale=0.8]{PhraseExtraction2.pdf}\\[1cm]}
\only<6>{\includegraphics[scale=0.8]{PhraseExtraction1.pdf}\\[1cm]}
\only<7>{\includegraphics[scale=0.8]{PhraseExtraction.pdf}\\[1cm]}
\end{center}
\end{exampleblock}
\only<2->{
\begin{unpacked_itemize}
\only<2>{\item Use a word-based translation model to annotate the parallel corpus with word-alignments}
\only<3->{\item $\langle$ Je, I $\rangle$, $\langle$ veux, want to $\rangle$, $\langle$ travailler, work $\rangle$}\only<4->{, $\langle$ ne veux pas, do not want to $\rangle$}\only<5->{, $\langle$ ne veux pas travailler, do not want to work $\rangle$}\only<6->{, $\langle$ Je ne veux pas, I do not want to $\rangle$}\only<7->{, $\langle$ Je ne veux pas travailler, I do not want to work $\rangle$}
\end{unpacked_itemize}
}
\end{frame}
\begin{frame}[t]{Models of translation}
\begin{exampleblock}{SCFG Rule extraction:}
\begin{center}
\only<1>{\includegraphics[scale=0.8]{HieroExtraction1.pdf}\\[1cm]}
\only<2>{\includegraphics[scale=0.8]{HieroExtraction2.pdf}\\[1cm]}
\only<3>{\includegraphics[scale=0.8]{HieroExtraction3.pdf}\\[1cm]}
\only<4>{\includegraphics[scale=0.8]{HieroExtraction4.pdf}\\[1cm]}
\end{center}
\end{exampleblock}
\begin{unpacked_itemize}
\only<1>{ \item X -> $\langle$ ne veux pas, do not want to $\rangle$ }
\only<2>{ \item X -> $\langle$ ne veux pas, do not want to $\rangle$, \item X -> $\langle$ ne X\ind{1} pas, do not X\ind{1} $\rangle$ }
\only<3>{ \item VP$/$NN -> $\langle$ ne veux pas, do not want to $\rangle$, \item VP$/$NN -> $\langle$ ne V\ind{1} pas, do not V\ind{1} $\rangle$ }
\only<4>{ \item X10 -> $\langle$ ne veux pas, do not want to $\rangle$, \item X10 -> $\langle$ ne X14\ind{1} pas, do not X14\ind{1} $\rangle$ }
\end{unpacked_itemize}
\end{frame}
%\begin{frame}[t]{Models of translation}
%\begin{block}{Hierarchical}
% \begin{center}
% \includegraphics[scale=0.55]{JeNeVeuxPasTravailler-Hiero.pdf}
% \hspace{0.3in}
% \includegraphics[scale=0.55]{JeVeuxTravailler-Hiero.pdf}
% \end{center}
%\end{block}
%\end{frame}
%\begin{frame}[t]{Impact}
% \begin{center}
% \includegraphics[scale=0.3]{ccb_tree.pdf}
% \end{center}
%\end{frame}
\begin{frame}[t]{Impact}
\vspace{0.5in}
\begin{table}
\begin{tabular}{l|rr}
\hline
Language & Words & Domain \\ \hline
English & 4.5M& Financial news \\
Chinese & 0.5M & Broadcasting news \\
Arabic & 300K (1M planned) & News \\
Korean & 54K & Military \\ \hline
\end{tabular}
\caption{Major treebanks: data size and domain \label{table_treebanks_size}}
\end{table}
\end{frame}
\begin{frame}[t]{Impact}
Parallel corpora far exceed treebanks (millions of words):
\begin{figure}
{\centering \includegraphics[scale=0.7]{resource_matrix.pdf}}
\end{figure}
\end{frame}
\begin{frame}[t]{Models of translation}
\begin{block}{Hierarchical}
\begin{center}
\includegraphics[scale=0.55]{JeNeVeuxPasTravailler-Hiero-labelled.pdf}
\hspace{0.3in}
\includegraphics[scale=0.55]{JeVeuxTravailler-Hiero-labelled.pdf}
\end{center}
\end{block}
\begin{itemize}
\item \alert{AIM: Implement a large scale open-source synchronous constituent learning system.}
\item \alert{AIM: Investigate and understand the relationship between the choice of synchronous grammar and SMT performance,}
\item \alert{AIM: and fix our decoders accordingly.}
\end{itemize}
\end{frame}
\begin{frame}[t]{Evaluation goals}
We will predominately evaluate using BLEU, but also use automatic structured metrics and perform small scale human evaluation:
\vspace{0.25in}
\begin{unpacked_itemize}
\item Evaluate phrasal, syntactic, unsupervised syntactic,
\item Aim 1: Do no harm (not true of existing syntactic approach)
\item Aim 2: Exceed the performance of current non-syntactic systems.
\item Aim 3: Meet or exceed performance of existing syntactic systems.
\end{unpacked_itemize}
\end{frame}
%\begin{frame}[t]{Impact}
%Success will have a significant impact on two areas of CL:
%\vspace{0.25in}
%\begin{unpacked_itemize}
%\item Machine translation
%\begin{unpacked_itemize}
% \item Make the benefits of richly structured translation models available to a much wider range of researchers and for a wider range of languages.
%% \item Change the research outlook of the field.
%\end{unpacked_itemize}
%\item Grammar induction:
%\begin{unpacked_itemize}
% \item Provide an empirical validation of state-of-the-art grammar induction techniques.
%\end{unpacked_itemize}
%\end{unpacked_itemize}
%\end{frame}
\begin{frame}[t]{Workshop Streams}
\vspace{0.25in}
\begin{unpacked_itemize}
\item Implement scalable SCFG grammar extraction algorithms.
\item Improve SCFG decoders to effieciently handle the grammars produce.
\item Investigate discriminative training regimes the leverage features extracted from these grammars.
\end{unpacked_itemize}
\end{frame}
\begin{frame}[t]{Language pairs (small)}
\begin{itemize}
\item BTEC Chinese-English:
\begin{itemize}
\item 44k sentence pairs, short sentences
\item Widely reported `prototyping' corpus
\item Hiero baseline score: 52.4 (16 references)
\item Prospects: BTEC always gives you good results
\end{itemize}
\item NIST Urdu-English:
\begin{itemize}
\item 50k sentence pairs
\item Hiero baseline score: MT05 - 23.7 (4 references)
\item Major challenges: major long-range reordering, SOV word order
\item Prospects: small data, previous gains with supervised syntax
\end{itemize}
\end{itemize}
\end{frame}
\begin{frame}[t]{Language pairs (large)}
\begin{itemize}
\item NIST Chinese-English:
\begin{itemize}
\item 1.7M sentence pairs, Standard NIST test sets
\item Hiero baseline score: MT05 - 33.9 (4 references)
\item Major challenges: large data, mid-range reordering, lexical ambiguity
\item Prospects: supervised syntax gains reported
\end{itemize}
\item NIST Arabic-English:
\begin{itemize}
\item 900k sentence pairs
\item Hiero baseline score: MT05 - 48.9 (4 references)
\item Major challenges: strong baseline, local reordering, VSO word order
\item Prospects: difficult
\end{itemize}
\item Europarl Dutch-French:
\begin{itemize}
\item 1.5M sentence pairs, standard Europarl test sets
\item Hiero baseline score: Europarl 2008 - 26.3 (1 reference)
\item Major challenges: V2 / V-final word order, many non-literal translations
\item Prospects: ???
\end{itemize}
\end{itemize}
\end{frame}
\begin{frame}[t]{Summary}
\begin{itemize}
\item Scientific Merit:
\begin{itemize}
\item A systematic comparison of existing syntactive approaches to SMT.
\item An empirical study of how constituency is useful in SMT.
\item An evaluation of existing theories of grammar induction in a practical application (end-to-end evaluation).
\end{itemize}
\item Potential Impact:
\begin{itemize}
\item Better MT systems, for more languages, across a range of domains.
\item More accessible high performance translation models for researchers. % all over the world.
\end{itemize}
\item Feasibility:
\begin{itemize}
\item A great team with a wide range of both theoretical and practical experience.
%\item Incremental plan without any deal breaking dependencies.
\item Solid preparation.
\end{itemize}
\item Novelty:
\begin{itemize}
\item First attempt at large scale unsupervised synchronous grammar induction.
% \item First study seeking to compare and understand the impact of synchronous structure on translation performance.
\end{itemize}
\end{itemize}
\end{frame}
\end{document}
|