Participation in the science workforce is low, and this can be partially attributed to low retention rates of undergraduate students who initially declare a science major. Low retention rates are further exacerbated for under-represented minority (URM) and first-generation (FG) college students pursuing science, and the existence of achievement gaps when compared with non-URM/non-first gen counterparts have been well documented. With the goal of implementing an intervention that would counteract these trends, I explored the design of, and the learning outcomes resulting from incorporating a metagenomics research curriculum for introductory undergraduate biology students majoring in science. Such interventions are purported to provide a pathway to help retain students interested in pursuing higher-education STEM degrees via increased achievement, improved attitudes, and greater self-efficacy. In this study, I measured these three general learning outcomes using a mixed-methods, quasi-experimental approach (including propensity score matching to decrease self-selection bias) to determine if these learning gains were predicted or mediated by the intervention. Results suggested achievement did not increase and attitudes do not become more favorable when incorporating the active learning modifications into the metagenomics research curriculum, specifically. However, students' final scores (especially those of URM/FG students) were significantly improved by having more active learning incorporated into the lecture component of the treatment group. In addition, students did articulate elements of engaging in mastery experiences in their metagenomic research and so it is possible that the research curriculum helped to increase their science self-efficacy to some extent. Future studies could investigate the relative efficacy of different types of active learning modifications on achievement and attitude and also incorporate a research experience of longer duration (i.e, >9h of lab work) to determine if increased time commitment to this type of research project improves learning outcomes. [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.]