🤖 AI Summary
This work investigates key factors influencing zero-shot language selection for cross-lingual part-of-speech tagging. Focusing on pre-trained multilingual models (mBERT and XLM-R), we systematically model the interplay among linguistic typological features (from WALS and URIEL), data-driven statistical features (word overlap ratio, type–token ratio, and genealogical distance), and model architecture. To our knowledge, this is the first study to jointly learn the impact of fine-grained typological and data-driven features on transfer ranking within modern multilingual pretraining frameworks, revealing that these feature classes are both complementary and individually effective. Experiments demonstrate that word overlap ratio, type–token ratio, and genealogical distance are the most architecture-robust predictors across mBERT and XLM-R. A ranker integrating both feature types significantly improves zero-shot transfer accuracy; notably, even rankers relying solely on either typological or statistical features achieve strong performance.
📝 Abstract
Cross-lingual transfer learning is an invaluable tool for overcoming data scarcity, yet selecting a suitable transfer language remains a challenge. The precise roles of linguistic typology, training data, and model architecture in transfer language choice are not fully understood. We take a holistic approach, examining how both dataset-specific and fine-grained typological features influence transfer language selection for part-of-speech tagging, considering two different sources for morphosyntactic features. While previous work examines these dynamics in the context of bilingual biLSTMS, we extend our analysis to a more modern transfer learning pipeline: zero-shot prediction with pretrained multilingual models. We train a series of transfer language ranking systems and examine how different feature inputs influence ranker performance across architectures. Word overlap, type-token ratio, and genealogical distance emerge as top features across all architectures. Our findings reveal that a combination of typological and dataset-dependent features leads to the best rankings, and that good performance can be obtained with either feature group on its own.