Combining Prediction, Syntactic Analysis and Semantic Analysis in Chinese Sentence Analysis

Abstract

results by semantic preferences on case structures The ABSTRACT basic principles of these two approaches were presented in This paper describes a system for the analysis of two papers by the current author [Yang, 1981, 1985]. The Chinese language that incorporates several heuristic tech- emphasis here is on incorporating these approaches into an niques for reducing ambiguities. effective analysis system. Heuristic knowledge about "characteristic " words is 2 PROCESSING FLOW AND CONTROL METHOD used to predict a partial syntactic structure of sentence before doing global analysis. More than one prediction may Thls system consists of four mapr components which exist, the system chooses the best combination of compati- perform segmentation, preprocessing, phrase structure ble partial predictions. Backtracking is evoked if acontradic- analysis, and case structure analysis These are illustrated in tion is later detected, producing a different choice of predic- figure 1 and explained below tions. Semantic constraints are used for translating phrase structure into case structure Rules are written to independent modules for word classes. An object-oriented scheme organizes the rules into layers, according to their priorities of application. A preference score is calculated at each step of processing, giving a synthetic evaluation of both syntactic plausibil- t ity and semantic plausibility. The scores of partial results steer a priority-driven parser towards the most plausible sentence structure, instead of generating all the possible results and afterwards making the choice. An experimental system based on these techniques has been built and tested on over one hundred sentences selected from published material. The results were very successful. The number of trees required to be produced in order to obtain a correct analysis was typically reduced from several hundred to under ten. 1 INTRODUCTION Figure 1 The