Research

Seven studies reviewed by the WWC investigated the effects of EIR^®. One study (Taylor, Frye, Short, & Shearer, 1991) is a randomized controlled trial that meets WWC evidence standards. The remaining six studies do not meet either WWC evidence standards or eligibility screens.

Taylor et al. (1991) conducted a randomized controlled trial of first grade teachers in two schools located in a Midwestern suburban school district. In each first grade classroom, five or six of the lowest-achieving students participated in the study. In all, 31 students in six classrooms were in the treatment group, and 28 students in six classrooms were in the comparison group.

Extent of evidence

The WWC categorizes the extent of evidence in each domain as small or medium to large (see the What Works Clearinghouse Extent of Evidence Categorization Scheme). The extent of evidence takes into account the number of studies and the total sample size across the studies that met WWC evidence standards with or without reservations.⁵

The WWC considers the extent of evidence for EIR^® to be small for alphabetics and comprehension. No studies that meet WWC evidence standards with or without reservations examined the effectiveness of EIR^® in the fluency or general reading achievement domains.