A researcher wanted to see how watching movies influenced subjects' IQ scores. She gave IQ tests to subjects following each of two movies. Half of the subjects first saw Titanic followed by Schindler's List , while the other half first saw Schindler's List and then Titanic . Varying the movie order is an example of
A) counterbalancing.
B) random sampling.
C) selection bias.
D) practice effects.

Question

Quizplus · Accepted Answer

Varying the movie order is an example of counterbalancing, which is a technique used to control for order effects in experimental designs. By administering the two movies in different order to different groups, the researcher can ensure that any observed differences in IQ scores are not simply due to the order in which the movies were viewed. Random sampling is a technique used to select participants for a study, selection bias refers to the distortion of results due to non-random selection of participants, and practice effects refer to improvements in performance on a task due to repeated exposure. None of these are relevant to the manipulation of movie order in this study.

A Researcher Wanted to See How Watching Movies Influenced Subjects