Bidirectional Multilingual Neural Machine Translation Between Regional Languages and Indonesian with the Transformer Model
DOI:
https://doi.org/10.24002/jbi.v17i2.15344Keywords:
Machine Translation, Multilingual, Neural Machine Translation, Regional Languages, Transformer, Bahasa DaerahAbstract
The limited digital linguistic resources for Indonesian regional languages remain a major obstacle to developing high-quality automatic translation systems. This study presents an empirical comparison of three multilingual Transformer based Neural Machine Translation (NMT) models, mT5, ByT5, and NLLB, for bidirectional translation between five Indonesian regional languages (Javanese, Sundanese, Balinese, Minangkabau, and Dayak Maanyan) and Indonesian under low-resource conditions. Using approximately 4,000 sentence pairs per language, the three models were evaluated with BLEU and ChrF++. Results show the bilingual baseline consistently outperformed the bidirectional multilingual approach across all three architectures, with NLLB proving most resilient to this degradation and achieving the strongest overall result (BLEU 62.16, ChrF++ 79.93) in controlled, domain-specific settings. This study contributes preliminary empirical evidence on architecture selection for low-resource regional language translation, constrained by dataset size and the absence of human evaluation.
Minimnya sumber daya linguistik digital untuk bahasa daerah Indonesia menjadi kendala utama dalam pengembangan sistem penerjemahan otomatis yang berkualitas. Penelitian ini menyajikan perbandingan empiris tiga model Neural Machine Translation (NMT) multilingual berbasis Transformer, yaitu mT5, ByT5, dan NLLB, untuk penerjemahan dua arah antara lima bahasa daerah Indonesia (Jawa, Sunda, Bali, Minangkabau, dan Dayak Maanyan) dan Bahasa Indonesia pada kondisi data terbatas. Menggunakan sekitar 4.000 pasangan kalimat per bahasa, ketiga model dievaluasi dengan BLEU dan ChrF++. Hasil menunjukkan model bilingual baseline secara konsisten mengungguli pendekatan multilingual bidirectional pada ketiga arsitektur, dengan NLLB paling tangguh terhadap penurunan performa dan mencatat hasil terbaik keseluruhan (BLEU 62,16; ChrF++ 79,93); hasil ini berlaku untuk kondisi yang terkontrol dan spesifik-domain. Penelitian ini memberikan bukti empiris awal mengenai pemilihan arsitektur untuk penerjemahan bahasa daerah, dengan keterbatasan pada ukuran dataset dan absennya evaluasi manusia.
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