Robust stochastic parsing: Comparing and combining two approaches for processing extra-grammatical sentences

This paper compares two techniques for robust parsing of extragrammatical natural language. Both are based on well-known approaches; one selects the optimal combination of partial analyses, the other relaxes grammar rules. Both techniques use a stochastic parser to select the “best” solution among multiple analyses. Experimental results show that regardless of the grammar, the best results are obtained by sequentially combining the two techniques, by first relaxing the rules and only when that fails by then selecting a combination of partial analyses.