Back to the Stats: Rescuing Low Resource Neural Machine Translation with Statistical Methods

M. Velayuthan, D. Jayakody, N. de Silva, A. Fernando, and S. Ranathunga Proceedings of the Ninth Conference on Machine Translation, 2024, pp. 901--907, This paper describes our submission to the WMT24 shared task for Low-Resource Languages of Spain in the Constrained task category. Due to the lack of deep learning-based data filtration methods for these languages, we propose a purely statistical-based, two-stage pipeline for data filtration. In the primary stage, we begin by removing spaces and punctuation from the source sentences (Spanish) and deduplicating them. We then filter out sentence pairs with inconsistent language predictions by the language identification model, followed by the removal of pairs with anomalous sentence length and word count ratios, using the development set statistics as the threshold. In the secondary stage, for corpora of significant size, we employ a Jensen-Shannon divergence-based method to curate training data of the desired size. Our filtered data allowed us to complete a two-step training process in under 3 hours, with GPU power consumption kept below 1 kWh, making our system both economical and eco-friendly. The source code, training data, and best models are available on the project's GitHub page.