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.