Title
MS-Ranker: Accumulating evidence from potentially correct candidates via reinforcement learning for answer selection
Abstract
Answer selection (AS) aims to select correct answers for a question from an answer candidate set. Conventional AS methods generally address this task by independently matching the question and each candidate. However, since the matching information between the question and a single candidate is usually limited, it is not enough to use the question as the only evidence to estimate the correctness of each candidate. To address this problem, we propose a novel reinforcement learning (RL) based multi-step ranking model, named MS-Ranker, which accumulates candidate. In specific, we explicitly consider the potential correctness of candidates when accumulating information and update the evidence with a gating mechanism. Moreover, as we use a listwise ranking reward, our model learns to pay more attention to the overall performance. Experiments on three benchmarks, namely WikiQA, SemEval-2016 CQA and SelQA, show that our model significantly outperforms existing methods that do not rely on external resources.
Year
DOI
Venue
2021
10.1016/j.neucom.2021.03.083
Neurocomputing
Keywords
DocType
Volume
Answer selection,Reinforcement learning,MS-Ranker,Gating mechanism,Listwise ranking reward
Journal
449
ISSN
Citations 
PageRank 
0925-2312
0
0.34
References 
Authors
0
5
Name
Order
Citations
PageRank
Yingxue Zhang100.68
Fandong Meng200.34
Peng Li314621.34
Ping Jian441.77
Jie Zhou51311.09