Educational Research and DevelopmentInteractions of independent variables in their effects on dependent variables are present whenever an effect holds for one kind of subject under one set of conditions but does not hold in the same way for other types of subjects or other sets of conditions. When interaction hypotheses guide research on in struction, the research enterprise is altered. The search for instructional tech niques, teaching styles, or media to provide the "best" overall results in teach ing-learning situations is abandoned because it is an inadequate guide for the design of instructional theory.What we know about individual differences leads us to believe that for certain subgroups of individuals, and under certain conditions, reports of overall results misrepresent the true effects. A wide range of instructional alternatives or treatments needs to be incorporated into research designs in order to determine those treatments that are particularly beneficial for particu lar subgroups of learners. Such research would be responsive to the question: Given this set of learner characteristics, what is the best way to tailor instruc-JOHN B. CARROLL, Educational Testing Service, was the editorial consultant for this chapter. White and Robert W. Douty assisted with the review of published research. Lola Rhea Appel typed the manuscript draft. We wish to thank DΓS. John B. Carroll and Fred N. Kerlinger for their help in conceptualizing the chapter and for their critical reactions to earlier drafts. Dr. Richard Snow also provided helpful comments from his reading of an earlier draft. Lastly, the authors would like to express their appreciation to Professors Lee J. Cronbach and Richard Snow for stimulating our interest in the concept of interaction in learning. 58 at University of British Columbia Library on June 22, 2015 http://rre.aera.net Downloaded from at University of British Columbia Library on June 22, 2015 http://rre.aera.net Downloaded from at University of British Columbia Library on June 22, 2015 http://rre.aera.net Downloaded from Review of Research in Education, 1 Bar-Yam, M. The interaction of student characteristics with instructional strategies: A study of students' performance and attitude in a high school innovative course. Unpublished doctoral dissertation, Harvard University, 1969. Beane, D. G. A comparison of linear and branching techniques of programed instruction in plane geometry. program for the Johnson-Neyman technique in the case of two groups, two predictor variables, and one criterion variable. Educational and Psychological Measurement, 1970,50, 121-132. Carry, L. R. Interaction of visualization and general reasoning abilities with instructional treatment in algebra. Unpublished doctoral dissertation, Stanford University, 1967. Cattell, R. B. Theory of fluid and crystallized intelligence: A critical experiment.
