As I promised earlier, I am reading the studies cited by Robert Marzano Classroom Instruction that Works. The first study I picked up is “The Effects of Homework on Learning: A Quantitative Synthesis” from Journal of Educational Research, November/December 1984 (full citation at end of this post).
Alfie Kohn’s claim in his rebuttal of my post at The Faculty Room was that none of the studies cited by Marzano, et. al. in the chapter “Homework and Practice” showed that “homework was beneficial for students.” Kohn accuses Marzano of misrepresenting the research on homework.
The focus of the Paschal, Weinstein, Walberg, 1984, which is not one of the five studies Kohn mentions in his criticism of Marzano, is a synthesis of “empirical studies of homework and of various homework strategies on the academic achievement and attitude of elementary and secondary students.” In the abstract of the study, Paschal, et. al. state: “About 85% of the effect sizes favored the homework groups. The mean effect size is .36 (probability less than .0001). Homework that was graded or contained teachers’ comments produced stronger effects (.80).”
As I said, this meta-analysis does not appear to be one of the five studies Kohn mentions in his post when questioning Marzano’s research, but it is in a chart on p. 61 of Marzano entitled “Research Results for Homework.” Perhaps it is not considered by Kohn because it is a meta-analysis or synthesis rather than original research itself. I do think it has interesting things to say about the effects of homework, however. Paschal, et. al. note that “[e]xtensive classroom research on ‘time on task’ and international comparisons of year-round time for study suggest that additional homework might promote U.S. students’ achievement.” However, the authors also note that writing on the subject of homework has largely characterized homework as “unwholesome, professionally unsupervised, or allow[ing] the children to practice mistakes.” Paschal, et. al. acknowledge that attitudes regarding homework seem to change depending upon a variety of factors.
Paschal, et. al. examined “15 studies that compared students with various qualities and amounts of assigned homework. These included the most frequent comparison, of students who were assigned and those who were not assigned homework.”
The authors conclude that “[t]he corpus of evidence shows a moderately large average effect size [0.80] of assigned homework that is commented upon or graded.” However, the authors also acknowledge that “much of the voluminous, 70-year-old literature on homework is opinionated and polemical, and surprisingly few methodologically adequate studies have been conducted.” I can attest to the veracity of the first part of that statement, given my own recent experience. Kohn was the only respondent to my original post who even brought up research.
Obviously, I want to read the five studies cited by Kohn and Marzano, as those studies seem to be at the heart of the contention between the two, but I felt this meta-analysis made it fairly clear that some homework was better than no homework. Marzano’s conversion table on p. 160 translates a 0.36 effect size to a percentile gain of 14. In other words, the average student who does homework (at least, according to my interpretation of the meta-analysis) will have score 14 percentage points higher on a standard bell curve measuring student achievement. An average student who does homework that is graded and receives feedback on that homework will have a score over 28 percentage points higher on a standard bell curve measuring student achievement. Sounds good to me. I encourage you to read the study yourself and draw your own conclusions, too. Feel free to leave them in the comments. I will be reading other studies and sharing my conclusions here, so if you are interested in the great homework debate, check back.
Marzano, Robert J., Debra J. Pickering, and Jane E. Pollock. Classroom Instruction that Works. Alexandria, VA: ASCD, 2001.
Paschal, Rosanne A., Thomas Weinstein, and Herbert J. Walberg. “The Effects of Homework on Learning: A Quantitative Analysis.” Journal of Educational Research. 78.2 (1984): 97-104. Professional Development Collection. EBSCO. Weber School Library, Atlanta, GA. 7 March 2008. <http://www.ebsco.com/>