The general sense of this term is used in LINGUISTICS, and especially in PSYCHOLINGUISTICS, where the phenomenon is subclassified into types, and the significance of ‘hesitation phenomena’ in terms of LANGUAGE-processing is discussed. Types of hesitation include silence, FILLED PAUSES (e.g. er, Japanese ano), elongated SYLLABLES (e.g. we-e-ll), repetitions (e.g. the-the thing . . . ), and so on. The DISTRIBUTION of these features is by no means random in speech, and it has been hypothesized that they occur at points where the speaker is planning new UTTERANCES. Based on the extent to which hesitations coincide with the boundaries between GRAMMATICAL, SEMANTIC, etc. CONSTITUENTS, the possibility has emerged that there may be more than one level of planning (e.g. syntactic, semantic, interactional) in SPEECH PRODUCTION.