Found effects

The WWC found Early Intervention in Reading^® to have potentially positive effects in the alphabetics and comprehension domains

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 +36 percentile points for the one study, with a range of +29 to +42 percentile points across findings. The improvement index for comprehension is +18 percentile points in the one study, with only one outcome measured.

Summary

The WWC reviewed seven studies on EIR^®. One of these studies meets WWC evidence standards. The remaining six studies do not meet either WWC evidence standards or eligibility screens. Based on the one study, the WWC found potentially positive effects on alphabetics and comprehension. The conclusions presented in this report may change as new research emerges.