Abstract: There are two kinds of parsing algorithms in nature language processing: one based on statistics and the other based on grammar rules. Earley algorithm is based on grammar rules. It can parse any context free grammar (CFG) without changing the grammar. This paper used several predictive strategies in Earley algorithm. These strategies come from LL, SLR and LR algorithms. Experiments were made for these strategies and their combinations. Results indicate that these strategics can usually reduce number of items and make parsing faster.

Key words: Context free grammar, Parsing, Earley algorithm