Educators and policymakers advocate for the implementation of problem-based approaches to STEM education in K-12 classrooms to help students develop 21st-century skills such as the ability to think critically, collaborate, and problem-solve. The first exploratory case study in this three-article dissertation examines how students engage in STEM-focused PBL experiences and the meaning of these experiences for the development of their STEM identities. The second study utilizes Braun and Clarke's reflective thematic analysis framework to explore the experience of a model STEM teacher at a high-performing STEM-focused elementary school as she implemented problem-based learning in the first year of a school-wide progressive reform initiative. Overall findings from the first two articles indicated missed opportunities to connect students' lived experiences to the problem-solving process. The final article in this study introduces the practice of asset mapping, which has traditionally been used in the field of social work and community development and applies it to the context of a STEM-focused PBL activity. The novel "Problem-based Learning through Asset Mapping (PLAM) Framework" recognizes the assets students bring to the learning process and supports educators aiming to leverage these assets to solve problems that are relevant and meaningful to learners. [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.]