Optimality Theory

Optimality theory (frequently abbreviated OT; second word normally capitalized by convention) is a linguistic model proposing that the observed forms of language arise from the interaction between conflicting constraints. OT differs from other approaches to phonological analysis, such as autosegmental phonology and linear phonology (SPE), which typically use rules rather than constraints. OT models grammars as systems that provide mappings from inputs to outputs; typically, the inputs are conceived of as underlying representations, and the outputs as their surface realizations.

There are three basic components of the theory:

Optimality theory assumes that these components are universal. Differences in grammars reflect different rankings of the universal constraint set, CON. Part of language acquisition can then be described as the process of adjusting the ranking of these constraints.

Optimality theory was originally proposed by the linguists Alan Prince and Paul Smolensky in 1993, and later expanded by Prince and John J. McCarthy. Although much of the interest in optimality theory has been associated with its use in phonology, the area to which optimality theory was first applied, the theory is also applicable to other subfields of linguistics (e.g. syntax and semantics).

Optimality theory is like other theories of generative grammar in its focus on the investigation of universal principles, linguistic typology and language acquisition.

Optimality theory also has roots in neural network research. It arose in part as an alternative to the connectionist theory of Harmonic Grammar, developed in 1990 by Géraldine Legendre, Yoshiro Miyata and Paul Smolensky. Variants of Optimality theory with connectionist-like weighted constraints continue to be pursued in more recent work (Pater 2009).

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