A reverse Hawthorne effect in educational evaluation

Abstract

An interesting finding noted in an evaluation of the effectiveness of broadcasting media in education revealed that the control class achieved higher posttest scores than the experimental classes. Although such a result is often considered to be due to measurement error, it was possible to test several hypotheses to explain it because of the vast amount of data gathered as part of a larger project. It was concluded that the teacher of the control class exerted greater effort in an attempt to express her dissatisfaction (a reverse Hawthorne effect) at not having been chosen to teach one of the more prestigious classes having supplementary TV or radio instruction. These results suggest that when experimental and control classes are housed at the same location, teachers of control classes may and can motivate their students so that their classes no longer provide a valid base-line to which experimental classes can be compared.