Self-control can be defined as the choice of a larger, more delayed reinforcer over a smaller, less delayed reinforcer, and impulsiveness as the opposite. A previous series of experiments in our lab (Forzano et al., 2014), used a within-subjects design with adult, human females to assess choices for two different reinforcers: preferred cartoon and preferred fruit juice. In the present experiment, choices were tested using both cartoon and juice reinforcers in a between-subjects design. In such an experimental design, two different groups of participants are assessed, one for each reinforce-type. The purpose of the current experiment is to determine whether or not the same results can be achieved, regardless of the experimental design. Comparing the results of the two sets of experiments, it was determined that there was a difference in the results in comparing the different reinforcers in the two experimental designs. In the within-subjects design experiment, a significant difference was found between the juice reinforcer condition and the cartoon reinforcer condition. These results have implications for future research concerning reinforcer differences and experimental design used for assessing choice in adult humans.