|
|
Effectiveness
Findings
The WWC review of interventions for beginning reading addresses student outcomes in four domains: alphabetics, fluency, comprehension, and general reading achievement. 1 The study included in this report covers one domain: general reading achievement. The findings below present the authors' estimates and WWC-calculated estimates of the size and the statistical significance of the effects of CWPT on students. 2
General reading achievement. Greenwood et al. (1993) reported a statistically significant effect of CWPT on the Comprehensive Test of Basic Skills–Reading. According to WWC analysis, however, the effect was not statistically significant. The effect size was large enough to be considered substantively important according to WWC criteria (that is, an effect size of at least 0.25).
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).
2 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. See the WWC Intervention Rating Scheme for the formulas the WWC used to calculate the statistical significance. In the case of CWPT, corrections for clustering were needed.
