Semantic Triple-Assisted Learning for Question Answering Passage Re-ranking

Dinesh Nagumothu, Bahadorreza Ofoghi, Peter W. Eklund

Abstract: Passage re-ranking in question answering (QA) systems is a method to reorder a set of retrieved passages, related to a given question so that answer-containing passages are ranked higher than non-answer-containing passages. With recent advances in language models, passage ranking has become more effective due to improved natural language understanding of the relationship between questions and answer passages. With neural network models, question-passage pairs are used to train a cross-encoder that predicts the semantic relevance score of the pairs and is subsequently used to rank retrieved passages. This paper reports on the use of open information extraction (OpenIE) triples in the form $${}$$ for questions and passages to enhance answer passage ranking in neural network models. Coverage and overlap scores of question-passage triples are studied and a novel loss function is developed using the proposed triple-based features to better learn a cross-encoder model to rerank passages. Experiments on three benchmark datasets are compared to the baseline BERT and ERNIE models using the proposed loss function demonstrating improved passage re-ranking performance.