Understanding and Mitigating Spurious Correlations in Text Classification with Neighborhood Analysis
This addresses a critical issue for NLP practitioners by mitigating spurious correlations in text classification, though it is incremental as it builds on existing regularization techniques.
The paper tackles the problem of spurious correlations in text classification, which degrade model performance on out-of-distribution data, by proposing a regularization method called NFL that improves robustness without auxiliary data.
Recent research has revealed that machine learning models have a tendency to leverage spurious correlations that exist in the training set but may not hold true in general circumstances. For instance, a sentiment classifier may erroneously learn that the token "performances" is commonly associated with positive movie reviews. Relying on these spurious correlations degrades the classifiers performance when it deploys on out-of-distribution data. In this paper, we examine the implications of spurious correlations through a novel perspective called neighborhood analysis. The analysis uncovers how spurious correlations lead unrelated words to erroneously cluster together in the embedding space. Driven by the analysis, we design a metric to detect spurious tokens and also propose a family of regularization methods, NFL (doN't Forget your Language) to mitigate spurious correlations in text classification. Experiments show that NFL can effectively prevent erroneous clusters and significantly improve the robustness of classifiers without auxiliary data. The code is publicly available at https://github.com/oscarchew/doNt-Forget-your-Language.