WSPAlign: Word Alignment Pre-training via Large-Scale Weakly Supervised Span Prediction

Most existing word alignment methods rely on manual alignment datasets or parallel corpora, which limits their usefulness. Here, to mitigate the dependence on manual data, we broaden the source of supervision by relaxing the requirement for correct, fully-aligned, and parallel sentences. Specifically, we make noisy, partially aligned, and non-parallel paragraphs. We then use such a large-scale weakly-supervised dataset for word alignment pre-training via span prediction. Extensive experiments with various settings empirically demonstrate that our approach, which is named WSPAlign, is an effective and scalable way to pre-train word aligners without manual data. When fine-tuned on standard benchmarks, WSPAlign has set a new state of the art by improving upon the best supervised baseline by 3.3 6.1 points in F1 and 1.5 6.1 points in AER . Furthermore, WSPAlign also achieves competitive performance compared with the corresponding baselines in few-shot, zero-shot and cross-lingual tests, which demonstrates that WSPAlign is potentially more practical for low-resource languages than existing methods. 1 (1) Data Collection and Annotation (2) Pre-training for word alignment Transformer Encoder Ashikaga Yoshimitsu was the third SEP … ⾜利 義満 は 室町 前期 の ¶ ¶ … Start End Source Paragraph Target Paragraph Alignment training data … Ashikaga Yoshimitsu was the third shogun of the Ashikaga shogunate. ⾜利義満は、室町時代前期の室町幕府第3代征夷⼤将軍 Cross-lingual ⾜利義満は、室町時代前期の… Ashikaga Yoshimitsu was the third shogun… 足利义满在任期间，南北朝获得统一… Ashikaga Yoshimitsu was the third shogun… Ashikaga Yoshimitsu war ein japanischer… Ashikaga unit les cours du Nord et du… Monolingual Ashikaga Yoshimitsu was the third shogun… In 1368 Yoshimitsu was appointed shogun… 足利义满在任期间，南北朝获得统一… 1358年9月25日足利义满出生，当时… Paragraph Pairs Collection Wiki word alignments Common word alignments … … Span Prediction Ashikaga Yoshimitsu was the third shogun… ⾜利義満は、室町時代前期の… Ashikaga Yoshimitsu was the third shogun… ⾜利義満は、室町時代前期の… Wiki Alignment Annotation Ashikaga Yoshimitsu war ein japanischer… Ashikaga Yoshimitsu was the third… Ashikaga Yoshimitsu war ein japanischer… Ashikaga Yoshimitsu was the third… Common Alignment Annotation Co-mentioned entity with Hyperlinks