Assessed the performance of 200 undergraduates working individually at hidden-word problems before an audience. 2 levels of audience status (peer or authority), evaluation (passive observation or performance rating), and time of audience activity (1-way mirror or video recording) were combined in a 2 * 2 * 2 design. There were 2 external control groups, one each for the 1-way mirror and video variables. The Palmar Sweat Index (PSI) was used to assess arousal level in all conditions. Analysis of variance showed a significant (p < .01) interaction between evaluation and time of action on the performance measure and a significant (p < .05) difference between the 1-way mirror condition and the corresponding control group. The PSI measure yielded a significant (p < .01) difference between the 2 times of action conditions. Results are interpreted as supporting notions of social facilitation theory. (21 ref.) (PsycINFO Database Record (c) 2016 APA, all rights reserved)