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Beginning Reading
PDF: Intervention Report (209 KB) PDF: Technical Appendices (391 KB)Improvement index
The WWC computes an improvement index for each individual finding. In addition, within each outcome domain, the WWC computes an average improvement index for each study and an average improvement index across studies (see Technical Details of WWC-Conducted Computations). The improvement index represents the difference between the percentile rank of the average student in the intervention condition versus the percentile rank of the average student in the comparison condition. Unlike the rating of effectiveness, the improvement index is entirely based on the size of the effect, regardless of the statistical significance of the effect, the study design, or the analysis. The improvement index can take on values between –50 and +50, with positive numbers denoting favorable results.
The average improvement index for alphabetics is +34 percentile points across three studies, with a range of –10 to +50 percentile points. For fluency, the average improvement index is +46 percentile points, with a range of +32 to +49 percentile points across outcomes in one study. For comprehension, the average improvement index is +14 percentile points across two studies, with a range of +6 to +21 percentile points. For the general reading domain, the average improvement index was +32 percentile points across five studies, with a range of –5 to +50 percentile points.
Summary
The WWC reviewed 106 studies on Reading Recovery®. Four of these studies meet WWC evidence standards; one study meets WWC evidence standards with reservations; the remaining 101 studies do not meet either WWC evidence standards or eligibility screens. Based on the five studies, the WWC found positive effects in alphabetics and general reading achievement and potentially positive effects in fluency and comprehension. The conclusions presented in this report may change as new research emerges.
|Institute of Education Sciences
