SPEECH DISFLUENCY AND THE STRUCTURE OF KNOWLEDGE

It is generally accepted that filled pauses ("uh," "er," and "um") indicate time out while the speaker searches for the next word or phrase. It is hypothesized that the more options, the more likely that a speaker will say "uh." The academic disciplines differ in the extent to which their subject matter and mode of thought require a speaker to choose among options. The more formal, structured, and factual the discipline, the fewer the options. It follows that lecturers in the humanities should use more filled pauses during lectures than social scientists and that natural scientists should use fewest of all. Observations of lecturers in 10 academic disciplines indicate that this is the case. That this is due to subject matter rather than to self-selection into disciplines is suggested by observations of this same set of lecturers all speaking on a common subject. In this circumstance, the academic disciplines are identical in the number of filled pauses used.