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.Gob 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 assigned to conditions in a way that balances out individual differences between them, including any potential differences in baseline levels of helpfulness. This helps to establish cause and effect relationships and rule out alternative explanations, such as Gob's suggestion that baseline differences in helpfulness could explain the results. Therefore, by using random assignment, Buster can argue that any observed differences in helping behavior between conditions are due to the effect of the film clip on mood rather than pre-existing differences between participants.

Buster Runs an Experiment in Which She Finds That Participants