Principles and parameters is a framework within
generative linguistics in which the
syntax of a
natural language is described in accordance with general
principles (i.e. abstract rules or
grammars) and specific
parameters (i.e. markers, switches) that for particular languages are either turned
on or
off. For example, the position of
heads in phrases is determined by a parameter. Whether a language is
head-initial or head-final is regarded as a parameter which is either on or off for particular languages (i.e.
English is
head-initial, whereas
Japanese is
head-final). Principles and parameters was largely formulated by the linguists
Noam Chomsky and
Howard Lasnik. Many linguists have worked within this framework, and for a period of time it was considered the dominant form of mainstream generative linguistics.