Experimental Design
The sample for this study includes students enrolled in grades 6–10 in 15 different middle and high schools in 5 school districts in California. The project took place over 2 years: 2 schools participated in 2008–2009, 12 schools participated in 2009–2010, and 1 school participated in both years. The 15 schools in the study span the Central Valley of California geographically. Overall, these schools are similar in size (749 students compared to 781 students), student to teacher ratio (20.4 to 22.6), and female to male student ratio (1.02 to 1.05) as California schools as a whole (US Department of Education 2011b). Our schools, however, are poorer (81 percent free or reduced price lunch compared with 57 percent) and have a higher percentage of minority students (82 percent to 73 percent) than the California average.
To identify children who did not have home computers, we conducted an in-class survey at the beginning of the school year with all of the students in the 15 participating schools. The survey, which took only a few minutes to complete, asked basic questions about home computer ownership and usage. In total, 7,337 students completed in-class surveys, with 24 percent reporting not having a computer at home. This rate of home computer ownership is roughly comparable to the national average. Any student who reported not having a home computer was eligible for the study and computers were given out to all eligible students. Treatment students received computers immediately, while control students had to wait until the end of the school year. Our main outcomes are all measured at the end of the school year, before the control students received their computers. All eligible students were given an informational packet, baseline survey, and consent form to complete at home. To participate, children had to have their parents sign the consent form (which, in addition to participating in the study, released future grade, test score, and administrative data) and return the completed survey to the school. Of the 1,636 students eligible for the study, we received 1,123 responses with valid consent forms and completed questionnaires (68.6 percent).