In their study, Hannel and Cuevas wonder if using computer-based simulation increase science achievement, motivation, efficacy and retention compared to the traditional hands-on manipulatives. To accomplish this, the researchers randomly divided 176 students from a middle class socioeconomic background, into ten classes. Five of those classes were control groups and the other five were experimental groups. The students in question were sixth grade students enrolled in the earth science program in the city of Atlanta, where they learn about geology, hydrology, meteorology and astronomy.