A processing model of phonological rule application.

Abstract

This dissertation proposes a formal model of phonological performance, Double Lookup, that also has empirical consequences for theories of phonological competence. The most significant of these is the Productivity Hypothesis, the claim that the ordering of rules derives from their relative productivity. According to Double Lookup, the use of phonological knowledge during speech production occurs in two steps. First, forms are retrieved from memory; second, phonological rules are retrieved from memory and applied, if appropriate, to the retrieved forms. Phonological patterns may be applied during speech in this way or be prepatterned (stored as patterns across lexical items in memory). The productivity of a rule is defined to be the likelihood of its being retrieved and applied during speech production. In general, less productive rules are more likely to be prepatterned than more productive rules. The Productivity Hypothesis then follows: Because prepatterned forms are retrieved before rules are retrieved and applied, less productive rules will be ordered before more productive rules. Double Lookup and the Productivity Hypothesis are tested in several ways. First it is shown that the ordering of partially productive rules in English, as determined using standard linguistic methods, corresponds with their ranking in productivity, as determined through experiments described in the literature and through original surveys of speech errors. The application of fully productive rules in English is also shown to be consistent with the Productivity Hypothesis; fully productive rules do not apply in a linear sequence, but rather interact in accordance with universal principles. All apparent counterexamples actually involve less than fully productive rules. Next it is shown that the phenomenon referred to in the literature as cyclicity is correctly predicted to arise under certain well-defined circumstances, as when a rule is both prepatterned and very productive. In addition, it is shown that there are large categories of examples that cannot be handled by the notion of cyclicity at all, but find a simple account within Double Lookup. Finally, evidence for the model is summarized by comparing it with other models of rule ordering which face conceptual and empirical problems Double Lookup avoids.