Robustification of Multilingual Language Models to Real-world Noise in Crosslingual Zero-shot Settings with Robust Contrastive Pretraining
Asa Cooper Stickland, Sailik Sengupta, Jason Krone, Saab Mansour, He He · 2023
Advances in neural modeling have achieved state-of-the-art (SOTA) results on public natural language processing (NLP) benchmarks, at times surpassing human performance.However, there is a gap between public benchmarks and real-world applications where noise, such as typographical or grammatical mistakes, is abundant and can result in degraded performance.Unfortunately, works which evaluate the robustness of neural models on noisy data and propose improvements, are limited to the English language.Upon analyzing noise in different languages, we observe that noise types vary greatly across languages.Thus, existing investigations do not generalize trivially to multilingual settings.To benchmark the performance of pretrained multilingual language models, we construct noisy datasets covering five languages and four NLP tasks and observe a clear gap in the performance between clean and noisy data in the zero-shot cross-lingual setting.After investigating several ways to boost the robustness of multilingual models in this setting, we propose Robust Contrastive Pretraining (RCP).RCP combines data augmentation with a contrastive loss term at the pretraining stage and achieves large improvements on noisy (& original test data) across two sentencelevel (+3.2%) and two sequence-labeling (+10 F1-score) multilingual classification tasks.Language Noise Injection Ratio Realistic Utt. % Realistic Examples (test-set) Unrealistic Examples (test-set) French (fr) 0.1 95.4% Me montré les vols directs de Charlotte à Minneapolis mardi matin .Quelle compagnie aérienne fut YX Me montré des vols entre Détroit er St. Louis sur Delta Northwest US Air est United Airlines .Lister des vols de Las Vegas à Son Diego German (de) 0.2 94.5% Zeige mir der Flüge zwischen Housten und Orlando Welche Flüge gibt es vom Tacoma nach San Jose Zeige mit alle Flüge vor Charlotte nach Minneapolis zum Dienstag morgen Zeige mit Flüge an Milwaukee nach Washington DC v. 12 Uhr