SimAlign: High Quality Word Alignments without Parallel Training Data using Static and Contextualized Embeddings

Sabet, Masoud Jalili; Dufter, Philipp and Schütze, Hinrich (27. April 2020): SimAlign: High Quality Word Alignments without Parallel Training Data using Static and Contextualized Embeddings. In: Findings of ACL: EMNLP 2020

Abstract

Word alignments are useful for tasks like statistical and neural machine translation (NMT) and annotation projection. Statistical word aligners perform well, as do methods that extract alignments jointly with translations in NMT. However, most approaches require parallel training data and quality decreases as less training data is available. We propose word alignment methods that require no parallel data. The key idea is to leverage multilingual word embeddings, both static and contextualized, for word alignment. Our multilingual embeddings are created from monolingual data only without relying on any parallel data or dictionaries. We find that alignments created from embeddings are competitive and mostly superior to traditional statistical aligners, even in scenarios with abundant parallel data. For example, for a set of 100k parallel sentences, contextualized embeddings achieve a word alignment F1 for English-German that is more than 5% higher (absolute) than eflomal, a high quality alignment model.

• Item Type: Journal article
• EU Funded Grant Agreement Number: 740516
• EU Projects: Horizon 2020 > ERC Grants > ERC Advanced Grant > ERC Grant 740516: NonSequeToR - Non-sequence models for tokenization replacement
• Research Centers: Center for Information and Language Processing (CIS)
• Subjects: 000 Computer science, information and general works > 000 Computer science, knowledge, and systems; 400 Language > 410 Linguistics
• Language: English