Inspired by the non-maximum suppression (NMS) algorithm (Rosenfeld and Thurston, 1971) that is used to prune redundant bounding boxes in object detection (Ren et al., 2015), we present a span-level NMS (Algorithm 1) to alleviate the problem.
removing both the retriever and the reranker performs the worst, which only achieves 68.1/81.0 F1 on two datasets at peak.