Work on summarization has explored both reinforcement learning (RL) optimization using ROUGE as a reward and syntax-aware models, such as models those input is enriched with part-of-speech (POS)-tags and dependency information. However, it is not clear what is the respective impact of these approaches beyond the standard ROUGE evaluation metric. Especially, RL-based for summarization is becoming more and more popular. In this paper, we provide a detailed comparison of these two approaches and of their combination along several dimensions that relate to the perceived quality of the generated summaries: number of repeated words, distribution of part-of-speech tags, impact of sentence length, relevance and grammaticality. Using the standard Gigaword sentence summarization task, we compare an RL self-critical sequence training (SCST) method with syntax-aware models that leverage POS tags and Dependency information. We show that on all qualitative evaluations, the combined model gives the best results, but also that only training with RL and without any syntactic information already gives nearly as good results as syntax-aware models with less parameters and faster training convergence.

本文比较了强化学习（RL）和基于句法的模型（如基于词性标注和依存信息的模型）两种文摘方法的优劣，并探究了它们在生成摘要时的影响，得出了使用两种方法的联合模型在质量评估方面表现最佳，但仅使用强化学习的训练无需更少的参数和更快的训练收敛即可得到与基于句法模型相近的好结果。

基于RL的句子摘要中语法蕴含的质量