Buster runs an experiment in which she finds that participants placed in a good mood by a happy film clip are more likely to offer help to a fellow participant than participants who see a sad film clip.Bob suggests that perhaps this difference simply results from the fact that the participants in the happy film clip condition were more helpful people______________to begin with.What methodological aspect of a successful experiment can Buster point to in order to refute this criticism?

Question

Quizplus · Accepted Answer

Random assignment ensures that participants are equally likely to be in any condition, thus controlling for pre-existing differences in traits like helpfulness.

Buster Runs an Experiment in Which She Finds That Participants