The study team collected data on the duration of the ERO classes as well as the frequency with which students attended the ERO classes and participated in other classes or tutoring services that aimed to improve their reading and writing skills.
ERO classes in the second year began an average of 2.3 weeks after the start of the school year and operated for an average of nine months. Eighteen schools started the ERO program on the first day of school, and five more schools started within the first two weeks that classes were in session. The remaining eleven started their ERO programs an average of seven weeks after the start of the school year. Among the students randomly assigned to the ERO group, 91 percent enrolled in the ERO classes, and 87 percent were still attending the classes at the end of the school year.
The ERO classes served as the primary source of literacy support services for students in the study sample. Although the largest difference in the use of supplemental literacy supports between the study’s ERO and non-ERO groups occurred in students' participation in a supplementary school-based literacy class (an average of 75 yearly sessions for ERO students and 17 yearly sessions for non-ERO students), ERO students were also significantly more likely to report working with a tutor in school (an average of 30 yearly sessions, compared with 12 yearly sessions for non-ERO students).