ABSTRACT
Students performed a simulated bank-proofing task individually in a lab with either the experimenter present or absent. Although run rates were similar, those in the Experimenter-Absent Group were off-task twice as much during sessions. Error frequencies for both groups were low and similar while rates of responding were significantly higher (+13%) in the Experimenter-Present Group because participants were off-task less often. Most human lab experiments fail to specify whether experimenters are present or absent in the room and this extraneous variable is a potential confound that should be controlled in future studies.
Disclosure statement
No potential conflict of interest was reported by the authors.