The consequences of Optimization for Underspecification

This paper argues for a theory in which underlying representation is determined solely by optimization with respect to the grammar, not by imposing any type of constraints directly on underlying representation. Past principles of underspecification are based on such grammar-blind principles as universal markedness ("Radical Underspecification") or underlying segment inventory ("Contrastive Specification"). I argue instead for an optimization approach to the lexicon, based on an expanded principle of Lexicon Optimization within Optimality Theory (Prince and Smolensky 1993), in which lexical representation is selected so as to optimize input-output mappings in grammar. In combination with a principle of Grammar Optimization, adapted from Kiparsky 1993, such that the optimal grammar preserves the most underlying structure, Lexicon Optimization results in a novel, utiliarian distribution of underspecification. Underspecification is used when there are alternant surface forms all of which are predictable from context or grammatical defaults. Nonalternating structure which does not condition alternations is, however, fully specified underlyingly. This need-based approach to underspecification overcomes objections raised to past theories of underspecification, rendering unnecessary certain recent attempts to eliminate underspecification from phonological theory (including Optimality Theory).A shorter version was presented at NELS 25: Proceedings of the North East Linguistics Society (1995) and is available at http://glsa.hypermart.net/Inkelas, S. (1995). The consequences of optimization for underspecification. In J.N. Beckman (Ed.), NELS 25: Proceedings of the North East Linguistics Society (pp. 287-302). Amherst, MA: GLSA (Graduate Linguistic Student Association), Dept. of Linguistics, University of Massachusetts