Environmental control in an experiment is necessary when ____ might influence the participants' reactions.
A) variation in instructions
B) physical conditions of the room
C) anticipation of the treatment
D) all of the above
E) none of the above

Question

Quizplus · Accepted Answer

Environmental control is necessary to reduce any extraneous variables that may affect the results of the study. Variation in instructions, physical conditions of the room, and anticipation of the treatment are all potential sources of variation that can be controlled through environmental control. Therefore, the best choice is D, all of the above.

Environmental Control in an Experiment Is Necessary When ____ Might