Procedure of Zimbardo's study
Controlled, participant, overt study.
Converted a basement of the Stanford University psychology building into a mock prison.
He advertised for students to play the roles of prisoners and guards for a fortnight- but ended early.
Participants were randomly assigned to either the role of prisoner or guard in a simulated prison environment.
Prisoners were 'arrested', blindfolded and stripsearched before being issued a uniform, and referred to by their number only- dehumanisation.
Guards were issued a khaki uniform, whistles, handcuffs and dark glasses (to make eye contact with prisoners impossible).
The guards worked shifts of eight hours each (the other guards remained on call). No physical violence was permitted.
Zimbardo observed the behaviour of prisoners and guards (as a researcher) and also acted as a prison warden.