Epistemic beliefs, epistemic cognitions, and self-regulation processes have a significant role in students' learning. Through this study, I investigated the role of mechanical engineering students' epistemic beliefs and epistemic cognitions involved in self-regulation processes while working on tasks with different difficulty levels. In this study, I used a qualitative instrumental-case research method. I used interviews and think-aloud to answer the research questions. The study was conducted in the Spring of 2022. Purposeful sampling was used to recruit fifteen undergraduate mechanical engineering students enrolled in the senior design class at the joint Florida Agricultural and Mechanical University (FAMU) and Florida State University (FSU) College of Engineering. The interviews explored engineering students' epistemic beliefs before starting to work on the tasks. On the other hand, think-aloud captured their epistemic cognitions and self-regulation processes while working on tasks of different levels of difficulty (i.e., simple and complicated). The data analysis revealed that mechanical engineering students have an absolutist epistemic belief system that values certainty and objectivity in knowledge. The study indicates that these beliefs do not hinder students' productivity or effectiveness. Instead, they allow students to focus on solving problems and achieving their goals with less work and time. Also, the study found that epistemic cognitions influenced how students approached tasks and the goals they set for themselves during the task definition and planning phases. Furthermore, epistemic cognitions influenced how students judged the quality of their work during the evaluation phase. The impact of epistemic cognitions were less influential during the strategy use phase. The results suggest that participants' epistemic beliefs and cognitions may be impacted by how they learned and studied in the past. Findings particularly suggest that participants were rewarded for solving problems quickly and efficiently. Identifying these constructs in the context of engineering helped show how engineering students approached engineering tasks and provided important implications for facilitating students' learning and engagement in engineering education. If we want students to think more creatively, we need to reward and teach them in different ways than what is traditionally used. We need to reward students for how they solve problems, not just for obtaining correct solutions quickly. This means recognizing creative thinking and problem-solving and rewarding these skills. It also means teaching students in ways that value mistakes and to see mistakes as learning opportunities. [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.]