A Researcher Conducts a Study in Which Participants Are Placed

Multiple Choice

A researcher conducts a study in which participants are placed in a simulated prison and assigned to roles as prisoners and guards.As part of the experimental briefing he gives participants clues about the hypothesis he is testing and about how he wants them to behave.Which of the following may compromise the internal and external validity of the research?

A) Experimenter bias.
B) Demand characteristics.
C) Regression to the mean
D) Both (a) and (b) .
E) All of the above.