Learning Corresponded Rationales for Text Matching
Authors: Mo Yu, Shiyu Chang, Tommi S Jaakkola
Keywords: interpretability, rationalization, text matching, dependent selection
TL;DR: We propose a novel self-explaining architecture to predict matches between two sequences of texts. Specifically, we introduce the notion of corresponded rationales and learn to extract them by the distal supervision from the downstream task.
Abstract: The ability to predict matches between two sources of text has a number of applications including natural language inference (NLI) and question answering (QA). While flexible neural models have become effective tools in solving these tasks, they are rarely transparent in terms of the mechanism that mediates the prediction. In this paper, we propose a self-explaining architecture where the model is forced to highlight, in a dependent manner, how spans of one side of the input match corresponding segments of the other side in order to arrive at the overall decision. The text spans are regularized to be coherent and concise, and their correspondence is captured explicitly. The text spans -- rationales -- are learned entirely as latent mechanisms, guided only by the distal supervision from the end-to-end task. We evaluate our model on both NLI and QA using three publicly available datasets.  Experimental results demonstrate quantitatively and qualitatively that our method delivers interpretable justification of the prediction without sacrificing state-of-the-art performance. Our code and data split will be publicly available.