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Searching for the Best Translation
Combination
Matīss RiktersDarba vadītāja: Dr. Dat., prof. Inguna Skadiņa
Doktorantūras seminārsRīga, Latvija
12. oktobris 2016
ContentsHybrid Machine TranslationMulti-System Hybrid MTSimple combining of translations
– Combining full whole translations– Combining translations of sentence chunks
Combining translations of linguistically motivated chunksSearching for the best translation combinationOther workFuture plans
Hybrid Machine Translation
Statistical rule generation– Rules for RBMT systems are generated from training corpora
Multi-pass– Process data through RBMT first, and then through SMT
Multi-System hybrid MT– Multiple MT systems run in parallel
Multi-System Hybrid MT
Related work:SMT + RBMT (Ahsan and Kolachina, 2010)Confusion Networks (Barrault, 2010)
– + Neural Network Model (Freitag et al., 2015)
SMT + EBMT + TM + NE (Santanu et al., 2014)Recursive sentence decomposition (Mellebeek et al., 2006)
Combining Translations
Combining full whole translations– Translate the full input sentence with multiple MT systems– Choose the best translation as the output
Combining full whole translations– Translate the full input sentence with multiple MT systems– Choose the best translation as the output
Combining translations of sentence chunks– Split the sentence into smaller chunks
• The chunks are the top level subtrees of the syntax tree of the sentence– Translate each chunk with multiple MT systems– Choose the best translated chunks and combine them
Combining Translations
Teikumu dalīšana tekstvienībās
Tulkošana ar tiešsaistes MT API
Google Translate Bing Translator LetsMT
Labākā tulkojuma izvēle
Tulkojuma izvade
Sentence tokenization
Translation with online MT
Selection of the best translation
Output
Whole translations
Teikumu dalīšana tekstvienībās
Tulkošana ar tiešsaistes MT API
Google Translate
Bing Translator LetsMT
Labāko fragmentu izvēle
Tulkojumu izvade
Teikumu sadalīšana fragmentos
Sintaktiskā analīze
Teikumu apvienošana
Sentence tokenization
Translation with online MT
Selection of the best chunks
Output
Syntactic analysis
Sentence chunking
Sentence recomposition
Chunks
Choosing the best
Choosing the best translation:KenLM (Heafield, 2011) calculates probabilities based on the observed entry with longest matching history :
where the probability and backoff penalties are given by an already-estimated language model. Perplexity is then calculated using this probability: where given an unknown probability distribution p and a proposed probability model q, it is evaluated by determining how well it predicts a separate test sample x1, x2... xN drawn from p.
An advanced approach to chunking– Traverse the syntax tree bottom up, from right to left– Add a word to the current chunk if
• The current chunk is not too long (sentence word count / 4)• The word is non-alphabetic or only one symbol long• The word begins with a genitive phrase («of »)
– Otherwise, initialize a new chunk with the word– In case when chunking results in too many chunks, repeat the process,
allowing more (than sentence word count / 4) words in a chunk
Linguistically motivated chunks
CICLing 2016
Selection of the best translation:12-gram LM trained with
– KenLM– DGT-Translation Memory corpus (Steinberger, 2011) – 3.1 million
Latvian legal domain sentences– Sentences scored with the query program from KenLM
Linguistically motivated chunks
CICLing 2016
Selection of the best translation:12-gram LM trained with
– KenLM– DGT-Translation Memory corpus (Steinberger, 2011) – 3.1 million
Latvian legal domain sentences– Sentences scored with the query program from KenLM
Test data– 1581 random sentences from the JRC-Acquis corpus– ACCURAT balanced evaluation corpus
Linguistically motivated chunks
CICLing 2016
Linguistically motivated chunks
CICLing 2016
Simple chunks Linguistically motivated chunks
• Recently
• there
• has been an increased interest in the automated discovery of equivalent expressions in different languages
• .
• Recently there has been an increased interest
• in the automated discovery of equivalent expressions
• in different languages .
Linguistically motivated chunks
CICLing 2016
Linguistically motivated chunks
Searching for the best
The main differences: • the manner of scoring chunks with the LM and selecting the best
translation• utilisation of multi-threaded computing that allows to run the
process on all available CPU cores in parallel• still very slow
Whole translations
System BLEUHybrid selection
Google Bing LetsMT Equal
Google Translate 16.92 100 % - - -
Bing Translator 17.16 - 100 % - -
LetsMT 28.27 - - 100 % -
Hybrid Google + Bing 17.28 50.09 % 45.03 % - 4.88 %
Hybrid Google + LetsMT 22.89 46.17 % - 48.39 % 5.44 %
Hybrid LetsMT + Bing 22.83 - 45.35 % 49.84 % 4.81 %
Hybrid Google + Bing + LetsMT 21.08 28.93 % 34.31 % 33.98 % 2.78 %
May 2015 results (Rikters 2015)
System
BLEU Hybrid selection
Whole translations Simple chunks Google Bing LetsMT
Google Translate 18.09 100% - -
Bing Translator 18.87 - 100% -
LetsMT 30.28 - - 100%
Hybrid Google + Bing 18.73 21.27 74% 26% -
Hybrid Google + LetsMT 24.50 26.24 25% - 75%
Hybrid LetsMT + Bing 24.66 26.63 - 24% 76%
Hybrid Google + Bing + LetsMT 22.69 24.72 17% 18% 65%
September 2015 (Rikters and Skadiņa 2016(1))
Simple chunks
System BLEU Equal Bing Google Hugo Yandex
BLEU - - 17.43 17.73 17.14 16.04
Whole translations – G+B 17.70 7.25% 43.85% 48.90% - -
Whole translations – G+B+H 17.63 3.55% 33.71% 30.76% 31.98% -
Simple Chunks – G+B 17.95 4.11% 19.46% 76.43% - -
Simple Chunks – G+B+H 17.30 3.88% 15.23% 19.48% 61.41% -
Linguistic Chunks – G+B 18.29 22.75% 39.10% 38.15% - -
Linguistic Chunks – G+B+H+Y 19.21 7.36% 30.01% 19.47% 32.25% 10.91%
Linguistically motivated chunks
January 2016 (Rikters and Skadiņa 2016(2))
Searching for the best
SystemBLEU
Legal General
Full-search 23.61 14.40
Linguistic chunks 20.00 17.27
Bing 16.99 17.43
Google 16.19 17.72
Hugo 20.27 17.13
Yandex 19.75 16.03
May 2016 (Rikters 2016 (2))
Start page
Translate with online systems
Input translations to combine
Input translated
chunks
Settings
Translation results
Input source sentence
Input source sentence
Interactive MS MT
• Matīss Rikters"Multi-system machine translation using online APIs for English-Latvian" ACL-IJCNLP 2015
• Matīss Rikters and Inguna Skadiņa"Syntax-based multi-system machine translation" LREC 2016
• Matīss Rikters and Inguna Skadiņa"Combining machine translated sentence chunks from multiple MT systems" CICLing 2016
• Matīss Rikters"K-translate – interactive multi-system machine translation"Baltic DB&IS 2016
• Matīss Rikters“Searching for the Best Translation Combination Across All Possible Variants”Baltic HLT 2016
Publications
CICLing 2016
• Matīss Rikters"Interactive Multi-system Machine Translation With Neural Language Models" IOS Press
• Matīss Rikters“Neural Network Language Models for Candidate Scoring in Hybrid Multi-System Machine Translation”CoLing 2016
Publications in progress
Neural Language Models
0.11
0.32
0.50
0.70
0.88
1.09
1.29
1.47
1.67
1.77
15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
16.00
17.00
18.00
19.00
20.00
21.00
22.00
23.00
24.00
25.00
Perplexity BLEU-HYLinear (BLEU-HY)
Epoch
Per
plex
ity
BLE
U
0.11
0.32
0.50
0.70
0.88
1.09
1.29
1.47
1.67
1.77
15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
13.30
13.80
14.30
14.80
15.30
15.80
16.30
Perplexity BLEULinear (BLEU)
Epoch
Per
plex
ity
BLE
U
Code on GitHubhttp://ej.uz/ChunkMT
http://ej.uz/SyMHyT
http://ej.uz/MSMT
http://ej.uz/chunker
http://ej.uz/NeuralLM
Code on GitHub
More enhancements for the chunking stepAdd special processing of multi-word expressions (MWEs)Try out other types of LMs
– POS tag + lemma– Recurrent Neural Network Language Model
(Mikolov et al., 2010)– Continuous Space Language Model
(Schwenk et al., 2006)– Character-Aware Neural Language Model
(Kim et al., 2015)Choose the best translation candidate with MT quality estimation
– QuEst++ (Specia et al., 2015)– SHEF-NN (Shah et al., 2015)
Handling MWEs in neural machine translation systems
Experiments on English – Estonian language pair
Future work
Citi darbi
• Pedagoģiskie darbi• Vadīti vairāki kursa un kvalifikācijas darbi• Vidējā atzīme 8.67• Studentu kurators
• Vasaras / ziemas skolas• Deep Learning For Machine Translation• ParseME 2nd Training School• Neural Machine Translation Marathon
References• Ahsan, A., and P. Kolachina. "Coupling Statistical Machine Translation with Rule-based Transfer and Generation, AMTA-The Ninth Conference of the Association for Machine Translation in the Americas." Denver, Colorado (2010).
• Barrault, Loïc. "MANY: Open source machine translation system combination." The Prague Bulletin of Mathematical Linguistics 93 (2010): 147-155.• Heafield, Kenneth. "KenLM: Faster and smaller language model queries." Proceedings of the Sixth Workshop on Statistical Machine Translation.
Association for Computational Linguistics, 2011.• Kim, Yoon, et al. "Character-aware neural language models." arXiv preprint arXiv:1508.06615 (2015).• Mellebeek, Bart, et al. "Multi-engine machine translation by recursive sentence decomposition." (2006).• Mikolov, Tomas, et al. "Recurrent neural network based language model." INTERSPEECH. Vol. 2. 2010.• Petrov, Slav, et al. "Learning accurate, compact, and interpretable tree annotation." Proceedings of the 21st International Conference on
Computational Linguistics and the 44th annual meeting of the Association for Computational Linguistics. Association for Computational Linguistics, 2006.
• Raivis Skadiņš, Kārlis Goba, Valters Šics. 2010. Improving SMT for Baltic Languages with Factored Models. Proceedings of the Fourth International Conference Baltic HLT 2010, Frontiers in Artificial Intelligence and Applications, Vol. 2192. , 125-132.
• Rikters, M., Skadiņa, I.: Syntax-based multi-system machine translation. LREC 2016. (2016)• Rikters, M., Skadiņa, I.: Combining machine translated sentence chunks from multiple MT systems. CICLing 2016. (2016)• Santanu, Pal, et al. "USAAR-DCU Hybrid Machine Translation System for ICON 2014" The Eleventh International Conference on Natural Language
Processing. , 2014.• Schwenk, Holger, Daniel Dchelotte, and Jean-Luc Gauvain. "Continuous space language models for statistical machine translation." Proceedings of
the COLING/ACL on Main conference poster sessions. Association for Computational Linguistics, 2006.• Shah, Kashif, et al. "SHEF-NN: Translation Quality Estimation with Neural Networks." Proceedings of the Tenth Workshop on Statistical Machine
Translation. 2015.• Specia, Lucia, G. Paetzold, and Carolina Scarton. "Multi-level Translation Quality Prediction with QuEst++." 53rd Annual Meeting of the Association
for Computational Linguistics and Seventh International Joint Conference on Natural Language Processing of the Asian Federation of Natural Language Processing: System Demonstrations. 2015.
• Steinberger, Ralf, et al. "Dgt-tm: A freely available translation memory in 22 languages." arXiv preprint arXiv:1309.5226 (2013).• Steinberger, Ralf, et al. "The JRC-Acquis: A multilingual aligned parallel corpus with 20+ languages." arXiv preprint cs/0609058 (2006).
References
Paldies!
