Most faculty in the Psychology Department believe that it is justified to link research participation to enrolment in psychology courses. While students provide a valuable service by donating a few hours to research, they are receiving something in return. One kind of return is the knowledge they receive from experiencing the role of a subject. Students then know directly what it is like to be a subject and come to understand the context in which psychological data are typically gathered. Also, experimenters provide feedback to subjects explaining their studies.
Students can learn the hypothesis and designs of the experiments in which they have participated.
Further, many undergraduates continue on to advanced work in which they conduct their own studies in laboratory or special problems courses. Having prior experience as subjects helps them design their own studies. Your instructor will have further information. It is your responsibility to satisfy the pre-screening requirement. This procedure will provide instructors with computer print-outs showing that you should get extra credit for their course.