Research has demonstrated the efficacy and effectiveness of using high preferred stimuli as reinforcers to change individual behavior. However, these high preferred reinforcers are not always readily available or it may not be in the individual's best interest to use them (i.e., high calorie edibles). Previous research has demonstrated that moderate and low preferred stimuli function as reinforcers (Graff, Gibson, & Galiatsatos, 2006). The effectiveness of such stimuli as reinforcers may depend on their potency. One way to quantify differences in reinforcer potency is through the use of progressive-ratio assessments. These assessments can be used to identify relative breakpoints for both high and moderate/low preferred stimuli to then use the difference in breakpoints to increase the reinforcer potency of moderate/low preferred stimuli used during behavior change programs, specifically during skill acquisition programs. Thus, the current study focused on evaluating the effects of enhanced low potency stimuli on skill acquisition. This purpose was explored in the context of two experiments. The research question for Experiment 1 was: Can contingency parameters be arranged so that the potency of moderate and high preferred stimuli that function as reinforcers can be equated in the context of a progressive-ratio schedule arrangement? The research question for Experiment 2 was: given that such a contingency arrangement can be identified and the potency of the moderate preferred stimuli can be equated with the potency of high preferred stimuli, how then do these contingency arrangements differ in the area of skill acquisition? Results of Experiment 1 demonstrated that the potency of the lesser preferred stimulus could be equated in the context of a progressive-ratio schedule for two out of the three participants. The results of Experiment 2 demonstrated that in the area of skill acquisition, enhanced low potency stimuli were as effective as reinforcers when compared to the high preferred stimuli during acquisition of novel or unmastered skills. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]