a1 University of Arizona
An evaluation metric in Universal Grammar provides a means of selecting between possible grammars for a particular language. The evaluation metric as conceived in Chomsky & Halle (1968; henceforth SPE) prefers the grammar in which only the idiosyncratic properties are lexically listed and predictable properties are derived. The essence of underspecification theory is to supply such predictable distinctive features or feature specifications by rule. Viewed in this way, the general idea of underspecification has always been a part of any theory of phonology that includes such an evaluation metric.
* I greatly appreciate discussions with Dick Demers, K. P. Mohanan, Dick Oehrle, Doug Saddy, Debbie Schlindwein, and, above all, Doug Pulleyblank in understanding the issues discussed here. A working version of this article was presented at the Northwest Linguistics Club, University of British Columbia; the ensuing discussion was helpful in clarifying issues, particularly that with Michael Rochemont and Patricia Shaw.