**Artificial Code-Switching in Pretraining for Multilingual Retrieval Robustness**

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: What is the effect of artificially code-switched pretraining data on the robustness of multilingual retrieval models against adversarial noise across different language pairs?

Autonomous synthesis report generated by Assignee Research. Tribunal consensus score: 8.8/10.