Human subject pools (HSPs) are the basis for much psychological research. There is an explicit assumption that participants receive benefits from their participation, however there is little empirical research about the costs/benefits of participation. We conducted two studies with undergraduate psychology students to evaluate factors that can affect the cost/benefit ratio. Study 1 (N = 46) examined Big Five personality characteristics and number of psychology courses taken, in relation to perceived benefits. There were depreciating returns for on-going participation but no personality differences in ratings. Study 2 (N = 50) used a quasi-experimental design to manipulate educational value. Half of the participants completed an educational assignment that integrated their HSP research experience into course material. Students who completed the educational assignment had a strong sense of contributing to scientific knowledge whereas students who had no such assignment did not. Implications for increasing educational value in HSPs are discussed.