Om Bhatt
2026
RBCorr: Response Bias Correction in Language Models
Om Bhatt | Anna A Ivanova
Proceedings of the Fifth Workshop on Generation, Evaluation and Metrics (GEM)
Om Bhatt | Anna A Ivanova
Proceedings of the Fifth Workshop on Generation, Evaluation and Metrics (GEM)
Language models (LMs) are known to be prone to response biases, which present as option preference biases in fixed-response questions. It is therefore imperative to develop low-cost and effective response bias correction methods to improve LM performance and enable more accurate evaluations of model abilities. Here, we propose a simple response bias correction strategy, RBCorr, and test it on 12 open-weight language models using yes-no, entailment, and multiple choice questions. We show that response bias is prevalent in LMs pre-correction and that RBCorr effectively eliminates bias and boosts model performance. We also explore the generalizability of bias behavior across models, datasets, and prompt formats, showing that LogProbs-based correction is highly dependent on all three of these aspects. Overall, RBCorr is an easy-to-use method that can boost the performance of smaller LMs and ensure that LM performance on closed-response benchmarks aligns more closely with their true capabilities.