Multi-Level Feature-Based Ensemble Model for Target-Related Stance Detection

Stance detection is the task of attitude identification toward a standpoint. Previous work of stance detection has focused on feature extraction but ignored the fact that irrelevant features exist as noise during higher-level abstracting. Moreover, because the target is not always mentioned in the text, most methods have ignored target information. In order to solve these problems, we propose a neural network ensemble method that combines the timing dependence bases on long short-term memory (LSTM) and the excellent extracting performance of convolutional neural networks (CNNs). The method can obtain multi-level features that consider both local and global features. We also introduce attention mechanisms to magnify target information-related features. Furthermore, we employ sparse coding to remove noise to obtain characteristic features. Performance was improved by using sparse coding on the basis of attention employment and feature extraction. We evaluate our approach on the SemEval-2016Task 6-A public dataset, achieving a performance that exceeds the benchmark and those of participating teams.