A Tree Probability Generation Using VB-EM for Thai PGLR Parser

In this paper, we applied VB-EM algorithm to generate a probability of constituent combination for PGLR parser. Three linguistic features which are simple PCFG, head-outward dependency and head-emission were calculated. The probabilities were used in a parsing process to find the best probable output tree. From our experiment, the parsing result from a combination of all features for first path and 3-best path are 56.61% and 78.58% respectively.