Congratulations to Eileen Blum who passed her dissertation defense on Sept. 2!
Title: The effects of non-linear data structures on the computation of vowel harmony
Committee: Adam Jardine, Bruce Tesar, Akinbiyi Akinlabi, and Eric Baković
Abstract: This dissertation develops a new theory of autosegmental locality for vowel harmony patterns. Vowel harmony (vh) is a pattern in which vowels within a word assimilate to a particular subsegmental feature. Phonological theory has proposed a variety of representational structures to describe the relationships between subsegmental features but little is known about the computational effects of these structures. In this dissertation I use Formal Language Theory from computer science to compare the computational complexity of vh patterns represented over strings and multi-tiered autosegmental representations (ARs). This comparison determines that multi-tiered ARs with “bottle brush” structures (Clements 1976; Hayes 1990; McCarthy 1988; Padgett 1995) are preferable to strings because they reduce the complexity of vh and create more concise descriptions of vh patterns. I thus propose a new complexity class called ASL V H to categorize vh patterns which are local over multi-tiered ARs. This new class crosscuts the established subregular stringset hierarchy (Rogers et al. 2013; Heinz, Rawal, and Tanner 2011; Rogers and Pullum 2011; Heinz 2018) because it includes patterns which when represented over strings are strictly local like in Akan, Bayinna Orochen, and Kinande; strictly piecewise like in Finnish; locally testable like in Tutrugbu; and it excludes the unattested first-last-harmony pattern which is star-free (Lai 2015; Jardine 2019). The ASLVH class encompasses vowel harmony patterns with both opaque and transparent vowels and predicts a new restriction on the locality of transparency. A contrast in the harmonic feature is shown to have no effect on the complexity of opaque vowels but it vastly increases the complexity of patterns with transparent vowels like the one in Eastern Meadow Mari.
Congratulations, Dr. Blum!
Congratulations are also in order for Eileen’s co-author Gina, seen here deep at work at her very important job: