Doubts on the reliability of parallel corpus filtering

초록

Parallel corpus filtering (PCF) aims to filter out low-quality data residing in parallel corpora. Recently, deep learning-based methods have been employed to assess the quality of sentence pairs in a parallel corpus, along with rule-based filtering that filters out noisy data depending on the pre-defined error types. Despite their utilization, to the best of our knowledge, a comprehensive investigation into the practical applicability and interpretability of PCF techniques remains unexplored. In this study, we raise two doubts on deep learning-based PCF: (i) Can deep learning-based PCF extract high-quality data? and (ii) Are scoring functions of PCF reliable? To answer these questions, we conduct comparative experiments on various PCF techniques with four datasets on two language pairs, English-Korean, and English-Japanese. Through the experiments, we demonstrate that the performance of the deep learning-based PCF highly depends on the targeting parallel corpus, and shows fluctuating adaptability depending on their characteristics. In particular, we figure out that high-scored sentences derived by the PCF technique do not necessarily guarantee high-quality results, rather it shows unintended preference.

키워드