Interpreting Pretrained Language Models via Concept Bottlenecks

Pretrained language models (PLMs) have made significant strides in various natural language processing tasks. However, the lack of interpretability due to their "black-box" nature poses challenges for responsible implementation. Although previous studies have attempted to improve interpretability by using, e.g., attention weights in self-attention layers, these weights often lack clarity, readability, and intuitiveness. In this research, we propose a novel approach to interpreting PLMs by employing high-level, meaningful concepts that are easily understandable for humans. For example, we learn the concept of "Food" and investigate how it influences the prediction of a model's sentiment towards a restaurant review. We introduce C3 M, which combines human-annotated and machine-generated concepts to extract hidden neurons designed to encapsulate semantically meaningful and task-specific concepts. Through empirical evaluations on real-world datasets, we show that our approach offers valuable insights to interpret PLM behavior, helps diagnose model failures, and enhances model robustness amidst noisy concept labels.