A study undertaken in which the researcher has control over some of the conditions in which the study takes place and control over some aspects of the independent variables being studied. Random assignment of the subjects to control and experimental groups is usually thought of as a necessary criterion of a true experiment. For example, if you interviewed moviegoers as they exited a theater to see if what they saw influenced their attitudes, this would not be experimental research; you had no control over who the subjects were or what film they watched or the conditions under which they watched it. On the other hand, if you chose a room, a film, and subjects to assign randomly to control and experimental groups and interviewed these subjects about the effects of the film on their attitudes, that would be an experiment.