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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
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


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.
Article:Version 1