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Effectiveness
Findings
The WWC review of interventions for middle school math addresses student outcomes in the math achievement domain.
Nunnery and Ross (2007) reported a positive and statistically significant effect of Accelerated Math on overall math achievement based on the Texas Learning Index math scores. After accounting for the misalignment between the school as the unit of assignment and the student as the unit of analysis, the WWC determined that this finding was neither statistically significant nor substantively important according to WWC criteria (an effect size greater than 0.25).5
Ysseldyke and Bolt (2007) examined two outcomes in this domain: the STAR Math test and Terra Nova math subtest. The authors reported a statistically significant positive effect for one outcome (STAR Math) and no statistically significant effect for the other (Terra Nova).6 After adjusting for misalignment between the classroom as the unit of assignment and the student as the unit of analysis, the WWC determined that, for both outcomes, the effects were neither statistically significant nor large enough to be considered substantively important according to WWC criteria.7
Ysseldyke and Tardrew (2007) reported a positive and statistically significant effect of Accelerated Math for the grade 6 classrooms on overall math achievement based on STAR Math scores. They also reported a positive, but not statistically significant, effect for the grade 7–8 Accelerated Math classrooms. After adjusting for misalignment between the classroom as the unit of assignment and the student as the unit of analysis, the WWC determined that neither finding was statistically significant nor large enough to be considered substantively important according to WWC criteria.8
In sum, in the math achievement domain the WWC reviewed findings from four samples reported in three studies.9 All four samples showed indeterminate effects. No studies implemented a strong design.
Rating of effectiveness
The WWC rates the effects of an intervention in a given outcome domain as positive, potentially positive, mixed, no discernible effects, potentially negative, or negative. The rating of effectiveness takes into account four factors: the quality of the research design, the statistical significance of the findings, the size of the difference between participants in the intervention and the comparison conditions, and the consistency in findings across studies (see the WWC Intervention Rating Scheme).
5 The level of statistical significance was reported by the study authors or, where necessary, calculated by the WWC to correct for clustering within classrooms or schools and for multiple comparisons. For an explanation, see the WWC Tutorial on Mismatch. For the formulas the WWC used to calculate the statistical significance, see Technical Details of WWC-Conducted Computations. In the case of Nunnery and Ross (2007), a correction for clustering was needed, so the significance levels may differ from those reported in the original study.
6 The study authors provided the WWC with findings for the WWC-relevant grade levels.
7 In the case of Ysseldyke and Bolt (2007), a correction for clustering was needed, so the significance levels may differ from those reported in the original study.
8 In the case of Ysseldyke and Tardrew (2007), a correction for clustering was needed.
9 The two grade-level cohorts—grade 6 and grades 7–8—in the Ysseldyke and Tardrew (2007) study were treated as separate studies because they examined the effects of Accelerated Math on different samples of students.
