The Weekly Newsletter of MIT Linguistics

Colloquium 4/8 - Stephanie S. Shih (University of Southern California)

Speaker: Stephanie S. Shih (University of Southern California)
Title: Lexically-conditioned phonology as multilevel grammar
Time: Friday, April 8th, 3:30pm – 5pm

Abstract: This talk takes up two interrelated issues for lexically-conditioned phonological patterns: (1) how the grammar captures the range of phonological variation that stems from lexical conditioning, and (2) whether the relevant lexical categories needed by the grammar can be learned from surface patterns. Previous approaches to category-sensitive phonology have focused largely on constraining it; however, only a limited understanding currently exists of the quantitative space of variation possible (i.e., entropy) within a coherent grammar. In this talk, I present an approach that models lexically-conditioned phonology as cophonology subgrammars of indexed constraint weight adjustments (i.e., ‘varying slopes’) in multilevel Maximum Entropy Harmonic Grammar. This approach leverages the structure of multilevel statistical models to quantify the space of lexically-conditioned variation in natural language data. Moreover, the approach allows for the deployment of information-theoretic model comparison to assess competing hypotheses of what the phonologically-relevant lexical categories are. Two case studies are examined: part of speech-conditioned tone patterns in Mende (joint work with Sharon Inkelas, UCB), and lexical versus grammatical word prosodification in English. Both case studies bring to bear new quantitative evidence to classic category-sensitive phenomena. The results illustrate how the multilevel approach developed here can capture the probabilistic heterogeneity and learnability of lexical conditioning in a phonological system.