This study is a large-scale, longitudinal evaluation comprising two main elements. The first element of the evaluation is an impact study designed to address the following questions:
To answer these questions, we based the impact study on a scientifically rigorous design—an experimental design that uses random assignment at two levels: (1) 50 schools from 27 school districts were randomly assigned to one of the four interventions; and (2) within each school, eligible children in grades three and five were randomly assigned to a treatment group or to a control group. Students assigned to the intervention group (treatment group) were placed by the program providers and local coordinators into instructional groups of three students. They received supplemental reading instruction in these small groups in addition to regular reading instruction they would have usually received—unless they were pulled out of class during their regular reading instruction time. Students in the control groups received the same instruction in reading that they would have ordinarily received. Children were defined as eligible if they were identified by their teachers as struggling readers and if they scored at or below the 30th percentile on a word-level reading test and at or above the 5th percentile on a vocabulary test. From an original pool of 1,576 third and fifth grade students identified as struggling readers, 1,502 were screened, and 1,042 met the test-score criteria. Of these eligible students, 779 were given permission by their parents to participate in the evaluation, and 772 were randomly assigned—558 to the treatment group and 214 to the control group.
The second element of the evaluation is an implementation study that has two components: (1) an exploration of the similarities and differences in reading instruction offered in the four interventions; and (2) a description of the regular instruction that students in the control group received in the absence of the interventions, and of the regular instruction received by the treatment group beyond the interventions.
Test data and other information on students, parents, teachers, classrooms, and schools were collected several times over a two-year period. Key data collection points include the period just before the interventions began, when baseline information was collected, and the periods immediately after and one year after the interventions ended, when follow-up data were collected.