Come join us for the last Phonology Circle of the semester, featuring a talk by Giorgio Magri.
Title: The Ranking Problem in Optimality Theory
Time: Wed 12/10, 5pm, 32-D831
Every learning problem can be formulated as an optimization problem: within a given typology, pick the grammar that is best given the data. Very little work has been done within Generative Grammar on how to actually solve the optimization problem itself. Recently, a small but growing body of literature within the framework of Optimality Theory (OT) has started to study the optimization problem itself. I will introduce the main ideas of this enterprise and I will illustrate it by focusing on a problem currently open in computational OT, namely that of devising incremental ranking algorithms that perform both promotion and demotion. I will explain why the problem is interesting. I will review one such algorithm, namely Boersma’s (1994) GLA. I will discuss why the algorithm does not work, by explaining in detail what goes wrong in the case of a counterexample discovered by Pater (2007). I will then note that the ranking problem within OT can be described as a linear feasibility problem. This very simple observation has far reaching consquences. In particular, it offers a straightforward way do device the desired incremental algorithm.