%A Paul Muter %A J.J. Furedy %A A. Vincent %A T. Pelcowitz %J Computers in Human Behavior %T User-hostile systems and patterns of psychophysiological activity %X Psychophysiological measures, which are not contaminated by demand characteristics, are potentially useful for improving systems and for examining psychological processes in human-computer interaction. In this study we report the use of minute-by-minute scored heart-rate (HR) and skin-conductance level (SCL) in a 25-subject experiment. Each subject was presented with two simulated bank-transaction tasks, one user-friendly and the other user-hostile. To check whether any differences were due simply to sheer difficulty, easy (forward digit-span) and hard (backward digit-span) memory tasks were presented to all subjects. The HR was higher during the computer (problem-solving) tasks than the memory tasks, but was unaffected by task difficulty, whereas SCL was uniquely elevated during the hard (user-hostile) computer task. The HR result is interpreted as reflecting parasympathetic withdrawal, while the SCL result suggests that the user-hostile software produced sympathetic excitation of the sort associated with the fight-or-flight reaction. SCL may serve as a good measure of user-friendliness. %K usability, psychophysiology %P 105-111 %V 9 %D 1993 %I Computers in Human Behavior %L cogprints4429