The goal of the Chinese Proposition Bank project is to create a corpus of text annotated with information about basic semantic propositions. Predicate-argument relations are being added to the syntactic trees of the Chinese Treebank.
Firstly, performances are heavily dependent on feature engineering, which needs domain knowledge and laborious work of feature extraction and selection. (性能依赖于特征工程,需要领域知识和大量的特征提取工作)
Secondly, although sophisticated features are designed, the long-range dependencies in a sentence can hardly be modeled. (没有特征能够表示长距离的依赖关系)
Thirdly, a specific annotated dataset is often limited in its scalability, but the existence of heterogenous resource, which has very different semantic role labels and annotation schema but related latent semantic meaning, can alleviate this problem. However, traditional methods cannot relate distinct annotation schemas and introduce heterogeneous resource with ease.(无法引入异构资源来解决数据不足的问题)
Feng Qian[3]提出将dependency tree structure通过architecture engineering的方法(而非feature engineering的方法)放入到LSTM cell中,能够充分利用句子的句法依存结果提高结果,网络结构如下所示。
Reference
http://verbs.colorado.edu/chinese/cpb/
Wang Z, Jiang T, Chang B, et al. Chinese semantic role labeling with bidirectional recurrent neural networks[C]//Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing. 2015: 1626-1631.
Qian F, Sha L, Chang B, et al. Syntax Aware LSTM model for Semantic Role Labeling[C]//Proceedings of the 2nd Workshop on Structured Prediction for Natural Language Processing. 2017: 27-32.