Despite multiple calls to action, the United States educational system is not producing enough viable contributors in the areas of science, technology, engineering, and mathematics (STEM). These fields continue to grow, and the STEM workforce continues to expand. However, the pool of citizens prepared to enter these professions is not keeping up with the demand. Part of this issue can be attributed to a diminishing interest in STEM by students, particularly during their identity forming adolescent years. Active learning strategies have proven successful in preventing this decline with project-based learning (PBL) being one of the most successful active learning strategies. In this study, STEM identity and engagement were measured for seventh grade students over the course of five months with a survey being administered prior to a PBL intervention, immediately after the intervention, and three months following the intervention to assess if there were perceived changes to both of these constructs over time. Results indicated that participation in a PBL unit had perceived effects on STEM identity but not engagement. More specifically, participants showed significant improvements in the areas of self-recognition and recognition by others. By engaging in the PBL intervention, students reported that they more closely aligned themselves with STEM and believed others also saw them more as "STEM people." No significant changes were found for engagement over the course of the study. A discussion of these results is followed by limitations of this study and implications for future research. [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.]