We demonstrate that our approach has a bigger impact on downstream QA approaches that use these justification sentences as additional signal than a strong baseline that relies on information retrieval (IR).
the contributions of this work are: (1) We propose an unsupervised, non-parametric strategy for the selection of justification sentences for multi-hop question answering (QA) that (a) maximizes the Relevance of the selected sentences; (b) minimizes the lexical Overlap between the selected facts; and (c) maximizes the lexical Coverage of both question and answer.