complexity (n.)

The general sense of this term is found in LINGUISTICS, with reference to both the FORMAL internal structuring of linguistic UNITS and the psychological difficulty in using or learning them. The factors which contribute to the notion of complexity are a major topic in PSYCHOLINGUISTICS, in studies of both adult COMPREHENSION and PRODUCTION, and of child language ACQUISITION. A central theme is the nature of the interaction between levels of difficulty in cognitive and linguistic STRUCTURES, and especially the way this affects the order of emergence of language patterns in children. However, it has not yet proved feasible to establish independent measures of complexity defined in purely linguistic terms, such as the number of TRANSFORMATIONS in a SENTENCE DERIVATION, or the number of FEATURES in the specification of a linguistic unit, largely because of controversy over the nature of the linguistic measures used, and the interference stemming from other psychological factors, such as the language user’s attention and motivation.

Several restricted senses of complex are also used (mostly contrasting with the term ‘simple’), e.g. ‘complex SENTENCE’ (in two senses: either a sentence consisting of more than one CLAUSE, or one consisting of a main clause and at least one SUBORDINATE clause), ‘complex PREPOSITION’ (a preposition consisting of more than one word), ‘complex word’ (one containing a free MORPHEME and at least one bound morpheme), ‘complex tone’ (an INTONATIONAL NUCLEUS with two distinct PITCH movements), ‘complex stop’ (a PLOSIVE with two points of ARTICULATION), ‘complex nucleus’ (a SYLLABIC peak with two distinct VOWEL qualities), ‘complex SEGMENT’ (a segment with two or more simultaneous oral tract CONSTRICTIONS, in some models of FEATURE theory), and so on. In GENERATIVE GRAMMAR, a ‘complex NP’ is a NOUN PHRASE with a clause as a COMPLEMENT (e.g. the assumption that the engine is working) or ADJUNCT (e.g. the assumption that he made). The ‘complex NP constraint’ in classical transformational grammar states that no element can be extracted out of a complex NP (e.g. *Who did you make the assumption that he liked?) – in other words, such constructions are syntactic ISLANDS.