40 American male volunteers attended a study on what they thought was on memory - specifically the effect of punishment on memory
Each ppt arrived at a lab in Yale. They met Mr Williams(researcher) and Mr Willis (fellow ppt), both of these were confederates
They drew straws to allocate roles - teacher and student, these roles were actually fixed and the ppt was always teacher
Mr Wallis was taken to his room and hooked up to a shock machine (strapped into his chair)
Ppts were taken to another room with the experimenter (they could hear mr Wallis but not see him)