Graph-Based Dependency Parsing with Recursive Neural Network

Graph-based dependency parsing models have achieved state-of-the-art performance, yet their defect in feature representation is obvious: these models enforce strong independence assumptions upon tree components, thus restricting themselves to local, shallow features with limited context information. Besides, they rely heavily on hand-crafted feature templates. In this paper, we extend recursive neural network into dependency parsing. This allows us to efficiently represent the whole sub-tree context and rich structural information for each node. We propose a heuristic search procedure for decoding. Our model can also be used in the reranking framework. With words and pos-tags as the only input features, it gains significant improvement over the baseline models, and shows advantages in capturing long distance dependencies.