Reanalysis and Limited Repair Parsing: Leaping off the Garden Path

This chapter develops a theory of reanalysis called limited repair parsing. Repair parsers deal with the problem of local ambiguity in part by modifying previously built structure when the chosen structure later proves to be inconsistent. This modification of existing structure distinguishes repair parsing from parallel or multi-path parsing, least-commitment parsing, backtracking, or reparsing strategies. Parsers with a limited capability for repair are psycholinguistically important because they can potentially explain the contrasts between difficult garden path structures (when repair fails) and unproblematic local ambiguities (when repair is successful or easy). Although the idea of repair has been implicit in some psycholinguistic work (and emerged explicitly in the diagnosis model of Fodor & Inoue, 1994, and the NL-Soar model of Lewis, 1993), there has been no clear formulation of the general class of repair parsers. This chapter makes a first step toward such a formulation, shows how repair parsing offers significant computational advantages over other alternatives for reanalysis, and proposes a particular repair mechanism, snip, that explains a wide range of cross-linguistic reanalysis phenomena. Snip is a proposal for a simple, automatic, on-line repair process. The chapter concludes by briefly describing how snip can be embedded in a more comprehensive sentence processing architecture that maintains the structural sensitivity of purely syntactic theories like Pritchett's (1992), yet still accounts for the flexibility of parsing as revealed by interactive studies.