Investigated changes in the uncertainty of linguistic decision making during a 1st encounter between 2 people. 5 male and 5 female undergraduates interacted with an E. It was hypothesized that as the interaction progressed, the increased feedback each interactor received would facilitate his linguistic choices. Filled pause rate and speech rate were used as indexes of uncertainty. As hypothesized, filled pause rate decreased and speech rate increased as the interaction progressed. The methodological significance of this time series analysis is demonstrated for an experiment concerning the effects of anxiety on speech. (PsycINFO Database Record (c) 2016 APA, all rights reserved)