A Meta-Analysis of Single Subject Design Writing Intervention Research

There is considerable concern that students do not develop the writing skills needed for school, occupational, or personal success. A frequent explanation for this is that schools do not do a good job of teaching this complex skill. A recent meta-analysis of trueand quasi-experimental writing intervention research (S. Graham & D. Perin, 2007a) addressed this issue by identifying effective instructional writing practices. The current review extends this earlier work by conducting a meta-analysis of single subject design writing intervention studies. The authors located 88 single subject design studies where it was possible to calculate an effect size. They calculated an average effect size for treatments that were tested in 4 or more studies, using a similar outcome measure in each study. This resulted in the identification of 9 writing treatments that were supported as effective. These were strategy instruction for planning/ drafting, teaching grammar and usage, goal setting for productivity, strategy instruction for editing, writing with a word processor, reinforcing specific writing outcomes, use of prewriting activities, teaching sentence construction skills, and strategy instruction for paragraph writing.