Article: The Effects of Nonpromotion on Elementary and Junior High School Pupils: A Mega-Analysis by C. Thomas Holmes & Kenneth M Matthews, University of Georgia, 1983. (The entire text is available free at the link.) (Paper presented to the Annual Meeting of the American Educational Research Association in Montreal Canada, April 1983.)
This one pulls together 44 studies to combine the data into one whole.
Because studies have variously analyzed the effects of nonpromotion on elementary and junior high school students--with some studies selecting control groups from within the same school and others without, some from age-peers and others from grade-peers--this meta-analysis mathematically integrates the research findings to coordinate their results. Using 44 studies that met the topic criteria, the authors measured the "effect sizes" in grand means.
When each effect size was treated equally, the grand mean effect size was -.37, indicating that promoted children scored 0.37 standard deviation units higher than retained children on the outcome measures. When effect sizes within each study were averaged, the grand mean was -.34. In studies in which promoted and nonpromoted students had been compared, the grand mean was -.38. It is noted that the high degree of consistency lends credibility to the validity of the findings. In addition to the grand means, the effect sizes were calculated on some dependent variable measures, including academic achievement, personal adjustment, attitude, behavior, and attendance.
The cumulative research shows that the potential for negative effects consistently outweighs positive outcomes. The analysis concludes with an extensive list of references.
Here's the article on academic achievement...which in my opinion is what school is supposed to be about!
The effect of nonpromotion on the academic achievement of pupils was measured in 31 of the 44 studies. From those studies, 367 effect sizes were calculated. When the mean of these 367 ESs was calculated, a value of -.44 was obtained indicating the promoted group, on the average, had achieved .44 standard deviation units higher than the retained group. Each of the sub-areas produced negative effect size values, indicating that non-promotion had a negative effect on pupils:
Language arts: -.40
Work-study skills: -.41
Social studies: -.35
Grade point average: -.58
I love studies that sum it up so nicely. Most of these studied have a line or two which completely echoes what we have been trying to get through to the kids' school. This one is particularly sweet:
Those who continue to retain pupils at grade level do so in spite of cumulative research evidence showing the potential for negative effects consistently outweighs positive outcomes. Since this cumulating research evidence consistently points to possibilities for negative effects to be produced by nonpromotion, the burden of proof should fall on the proponents of retention plans to show there is compelling logic indicating success of their plans, when so many other plans have failed.