Subject effects in laboratory research: An examination of subject roles, demand characteristics, and valid inference

Presents 4 conceptualizations of the role that Ss adopt in laboratory experiments, and assesses empirical support for each. There is no unconfounded evidence that Ss adopt a good S role and seek to confirm hypotheses or that they adopt a negativistic role and seek to sabotage experiments. There is some evidence that in specific contexts Ss may adopt a faithful S role, and there is considerable evidence that Ss are apprehensive about how their performance will be evaluated. Furthermore, providing S with a hypothesis about a study consistently produces bias. These relationships are then examined with respect to their implications for improving research in general and for drawing valid inferences from experimental data. (69 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved).