Leveraging Hierarchical Deep Semantics to Classify Implicit Discourse Relations via a Mutual Learning Method

Abstract

This article presents a mutual learning method using hierarchical deep semantics for the classification of implicit discourse relations in English. With the absence of explicit discourse markers, traditional discourse techniques mainly concentrate on discrete linguistic features in this task, which always leads to a data sparseness problem. To relieve this problem, we propose a mutual learning neural model that makes use of multilevel semantic information together, including the distribution of implicit discourse relations, the semantics of arguments, and the co-occurrence of phrases and words. During the training process, the predicting targets of the model, which are the probability of the discourse relation type and the distributed representation of semantic components, are learned jointly and optimized mutually. The experimental results show that this method outperforms the previous works, especially in multiclass identification attributed to the hierarchical semantic representations and the mutual learning strategy.