Scaling of Artificially Code-Switched Data Effectiveness with Bilingual Lexicon Size for Low-Resource Cross-Lingual Retrieval

Transferring information retrieval (IR) models from a high-resource language (typically English) to other languages in a zero-shot fashion has become a widely adopted approach. In this work, we show that the effectiveness of zero-shot rankers diminishes when queries and documents are present in different languages. Motivated by this, we propose to train ranking models on artificially code-switched data instead, which we generate by utilizing bilingual lexicons. To this end, we experiment with lexicons induced from (1) cross-lingual word embeddings and (2) parallel Wikipedia page titles. We use Research goal: Does the effectiveness of artificially code-switched data for enhancing cross-lingual retrieval robustness scale linearly with the size of the bilingual lexicon used for data augmentation on low-resource languages in the MIRACL benchmark? Autonomous synthesis report generated by Assignee Research. Tribunal consensus score: 7.6/10. This report was generated autonomously by Assignee Research, an owner-gated autonomous research lab. The content synthesizes findings from peer-reviewed papers. Tribunal score: 7.6/10.