Routledge Dictionary of Language and Linguistics.pdf

A-Z 1243realized form becomes more and more restricted with regard to requirements such aslearnability ( abstractness controversy).phonologyReferencesunderlying representationformunderlyingunderlying structuredeep structureunificationunification grammarunification grammar1 In its broadest sense, an umbrella term for all generative grammar models, especiallythose generative grammars that use a unification operation in their rule systems.2 In a narrower sense, a member of a family of newer grammatical models in whichfeature unification is used (usually in conjunction with other feature operations) tocapture the information flow in derivation. Various particular approaches belong to thisgroup: grammatical models like Generalized Phrase Structure Grammar (GPSG) andLexical-Functional Grammar (LFG), grammatical formalisms capable of producingexpressions for implementation on the computer, like Functional Unification Grammar(FUG) and PATR-II; as well as a series of newer models that present forms mixed fromexisting approaches and theories like Head-driven Phrase Structure Grammar(HPSG) and Categorial Unification Grammar (CUG). Since all these models weredeveloped at Stanford University and at neighboring institutions in the San Francisco BayArea, they are known as Bay Area Grammars. Other terminology includes UnificationbasedGrammars, Constraint-based Grammars, and Information-based Grammars.Unification grammar is based on the further development of linguistic features. Everylinguistic unit (word or phrase) is characterized by a feature structure, that is, by anumber of attribute-value pairs, whose values can be either atomic symbols or feature