The primary purpose of this study was to examine the influence of volunteer motivation, participation, and citizen science project type on the retention and scientific literacy of 4-H youth volunteers ages 8-19 years participating in science projects. The conceptual model of participation in organized activities (OA) proposed by Bohnert, Fredericks and Randall (2010) was used as a framework for the variables included in the study categorizing them as predictors of participation, participation, program characteristics, or outcomes. A systematic review of volunteer motivations, retention, and scientific literacy in citizen science projects exposed that the literature contains silos of information published in content area specific journals further supporting the need for the Journal of Citizen Science Practice and Theory established in 2016. The review revealed a gap in the literature on motivations of youth citizen science, the factors that influence volunteer retention in citizen science projects, and how to define and measure scientific literacy. This study found two significant differences between 4-H youth participants in 4-H science programs and those in 4-H citizen science program. First, youth in science programs without a citizen science component were more motivated by social functions to volunteer and second, they are more likely to continue to volunteer than their counterparts. Further investigation into the influence of citizen science program characteristics on these variables is needed. This study revealed relationships between engagement and consistency, in addition to consistency and both retention and scientific literacy outcomes. These relationships need to be examined for causation. A new framework for studying youth participation and youth outcomes in citizen science programs is proposed. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]