The bi-directional relationships within the personal and contextual environments of adolescents are critical to the development of adolescents and their transition into adulthood. Opportunities for youth to participate in and provide leadership in meaningful programs, gain life skills, and interact with adults in sustained relationships are key features leading to positive youth development (PYD). Youth engagement in research and evaluation is described as an engaging pathway to PYD. The purpose of this study was to measure changes in levels of PYD through adolescent participation in youth participatory evaluation and youth community action training (YPE/YCAT). Seventy-four conveniently sampled senior 4-H members from eight Oregon County 4-H programs participated in a longitudinal study over the course of six months. Each county was represented by a treatment and comparison group. County teams in the treatment group were trained in youth participatory evaluation and youth community action (YPE/YCA). The county teams within the treatment group were expected to return to their respective counties and conduct youth participatory evaluation (YPE) projects using community issues forums. Significantly and consistently higher levels of the PYD indicators of competence, confidence, connection, character, caring, and contribution (six Cs) were predicted for the treatment group participating in YPE/YCAT relative to the comparison group not participating in YPE/YCAT. A multi-dimensional survey comprised of the Generalized Self-Efficacy Scale (competence), the Rosenberg Self-Esteem Scale (confidence), and Connection, Character, Caring and Contribution Scales was emailed monthly over the course of six months, via Survey Monkey, to the 74 subjects in the eight counties. Twenty-three subjects (31%) completed the survey at all six time points: 14 subjects in the treatment group and nine in the comparison group. Given the small sample size, age, gender, and ethnicity were not considered in the analysis. The nonparametric Mann-Whitney U and Wilcoxon Signed Rank Tests were used to analyze the data. The dependent variables included competence, confidence, connection, character, caring, and contribution as indicators of PYD. The independent variable consisted of YPE/YCAT administered to the treatment group. The one-tailed Mann-Whitney U Test found no significant and consistent differences (p greater than 0.05) in mean scores between the treatment and comparison groups relative to the six Cs following the training of the treatment group in YPE/YCA. The one-tailed Wilcoxon Signed Rank Test found no significant and consistent differences (p greater than 0.05) in scores within the treatment group relative to the six Cs following the training of subjects in YPE/YCA. The treatment group's participation in YPE/YCAT did not significantly and consistently affect the levels of competence, confidence, connection, character, caring, and contribution as indicators of PYD. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]