| ROA: | 198 |
|---|---|
| Title: | Similarity and Frequency in Phonology |
| Authors: | Stefan Frisch |
| Comment: | Northwestern U. PhD thesis. Word Perfect document requires SIL Doulos IPA font. Postscript document (listed as Part 2) in 3 sections of 3 MB each (unzipped). This thesis is also available from the author if you have technical difficulties. The last poscri |
| Length: | 185 |
| Abstract: | This thesis focuses upon parallels between phonology and phonological processing. I study phonological speech errors and a phonotactic dissimilarity constraint, demonstrating they have analogous similarity and frequency effects. In addition, I show that abstract phonological constraints are influenced by the phonological encoding of lexical items. The results of this thesis are based on a metric of similarity computed using the representations of STRUCTURED SPECIFICATION (Broe 1993). This metric is quantitatively superior to traditional metrics of similarity which are based on feature counting. I also employ a probabilistic model of a gradient linguistic constraint which is based on categorical perception. In this model, the acceptability of a form is gradient, and acceptability is correlated with frequency. The most acceptable forms in a language are the most frequent ones. This constraint model provides a better fit to gradient phonotactic data than traditional categorical linguistic constraints. Together, the similarity metric and gradient constraint model demonstrate that statistical patterns in language can be relevant, principled, and formally modeled in linguistic theory. The primary case which is studied is the OCP-PLACE constraint within the verbal roots of Arabic. Using the gradient constraint model, I show that similarity effects in OCP-Place are stronger word initially than later in the word. A parallel pattern is experimentally demonstrated for speech errors. I claim that the effect for speech errors follows from the fact that production of segmental material in a lexical item is inherently temporal. I argue that segmental information in lexical representations is sequentially accessed even for abstract phonological purposes, like phonotactics. The effects of word position on similarity in both speech production and phonotactics are accounted for in a connectionist model of lexical access, which does not differentiate the storage of a representation from its use. Traditional phonological representations are not temporally encoded, and thus cannot account for these effects. Structured specification is incompatible with UNDERSPECIFICATION (Kiparsky 1982, Archangeli 1984). In underspecification, features are left blank in a linguistic representation to capture redundancy relationships and phonological markedness. I demonstrate that models of similarity in phonotactics and speech errors which use underspecification do not model the data as well as the similarity metric based on structured specification. The data presented in this thesis present a challenge to all current phonological theories. My approach shares with Optimality Theory the notion of a violable constraint, but attaches quantitative significance to degrees of violability. Forms which violate many constraints, or violate a constraint strongly, are found less frequently than forms which do not. The OCP-Place constraint is truly gradient, and the cumulative interaction of multiple OCP-Place violations is quantitative, not categorical. As in Declarative Phonology, constraint satisfaction is simultaneous, not ranked. However, the quantitative nature of the constraints and constraint interaction allows relative ranking via weighting. |
| Type: | Dissertation |
| Area/Keywords: | |
| Article: | Version 1 |