Multi-Document Summarization Model Based on Redundancy-Constrained Knapsack Problem

Abstract

In this study, we regard multi-document summarization as a redundancy-constrained knapsack problem. The summarization model based on this formulation is obtained by adding a constraint that curbs redundancy in the summary to a summarization model based on the Knapsack problem. As the redundancy-constrained knapsack problem is an NP-hard problem and its computational cost is high, we propose a fast decoding method based on the Lagrange heuristic to quickly locate an approximate solution. Experiments based on ROUGE evaluation show that our proposed model outperforms the state-of-the-art text summarization model, the maximum coverage model, in finding the optimal solution. We also show that our decoding method finds a good approximate solution, which is comparable to the optimal solution of the maximum coverage model, more than 100 times faster than an integer linear programming solver.