Positive Grammar Checking: A Finite State Approach

This paper reports on the development of a finite state system for finding grammar errors without actually specifying the error. A corpus of Swedish text written by children served as the data. Errors are more frequent and the distribution of the error types is different than for adult writers. Our approach (following Karttunen et al. [9]) for finding errors involves developing automata that represent two “positive” grammars with varying degree of detail and then subtracting the detailed one from the general one. The difference between the automata corresponds to a grammar for errors. We use a robust parsing strategy which first identifies the lexical head of a phrase together with the lexical string which precedes it beginning at the left margin of the phrase. The technique shows good coverage results for agreement and verb selection phenomena. In future, we aim to include also the detection of agreement between subject and predicative complements, word order phenomena and missing sentence boundaries.