Applying tree kernel to Chinese syntactic parsing reranking

Chinese Syntactic Parsing is often divided into two stages, basic model to generate k-best candidate parsing trees and reranking stage to find the best one in these trees, and we focus on the second stage-reranking. Tree kernel has been used in Syntactic parsing in English(Collins 2002) which makes a good improvement in performance. This paper makes tree kernel method practical for Chinese Syntactic Parsing, and improves tree kernel from three points: the first is introducing rules weights rw to distinct different rules, the second is introducing similar rules converging, and the third is introducing a parameter lambda to scale the relative importance of tree fragments with their size and solve the peak problem which is a common kernel. Experiments show that these three adjustments to tree kernel increase reranking performance a lot.