Dissertation - Michael Becker

CHAPTER 5CONCLUSIONS AND FUTURE DIRECTIONS5.1 Summary of the dissertationThis dissertation started with two empirical observations about two biases that humanshave in their treatment of their lexicon:They ignore unnatural interactions betweenphonological elements (chapter 2), and they state generalizations based on the surfaceproperties of lexical items (chapter 3). These observations were taken as evidence fora model of grammar that has built-in expectations about the naturalness of phonologicaloperations, and that states phonological generalizations in terms of constraints on surfaceforms. As it happens, Optimality Theory (Prince & Smolensky 1993/2004) is such a model,and this work developed an OT-based model for learning lexically-specific phonology andfor projecting the learned statistics onto novel items (chapter 4).In Turkish, voicing alternations affect stem-final stops in some nouns (e.g. tat ∼ tad-1 ‘taste’), but not in others (e.g. at ∼ ad-1 ‘horse’). While it is not predictable whetherany given lexical item will voice or not, voicing alternations are tightly correlated withthe phonological shape of nouns when averaged over the lexicon. Specifically, voicingalternations are correlated with the size of nouns, with the identity of the final stops, andwith the height and backness of the noun’s last vowel. When learning their language,Turkish speakers don’t content themselves with learning the behavior of individual items;they also learn about correlations between the shapes of nouns and the likelihood that theywill display voicing alternations, and when given a novel noun, they match its likelihood ofalternation to the likelihood of alternation of similar nouns. The question was what nounscount as being similar to the given novel noun. It turned out that the size of the noun and220