My dissertation examines undergraduates' online learning experiences during the COVID-19 pandemic through three distinct studies. The primary goal of my dissertation is to shed light on crucial aspects of social cognitive learning theories and learning experience design (LXD) applied in distance learning. These studies, using an LXD approach integrated with cognitive science theory, revealed that online video-based instruction can lead to reduced mind wandering, increased engagement, and improved retention of key conceptual knowledge. This is achieved through questions embedded into videos and thoughtful LX design choices that consider individual differences in self-regulation, self-efficacy, and anxiety. In Study 1, I evaluate the impact of experiences with video-based online educational technology on student learning using theories of cognitive engagement and mind-wandering. Using Structural Equation Modeling (SEM) and survey data collected from 14 classes in California (n = 633), I validate that self-efficacy, task-value, and trait anxiety directly influence learners' engagement. Additionally, I find that self-efficacy and trait anxiety as significant sources of students' mind-wandering, with mind-wandering partially mediating the relationship between self-efficacy and engagement. These findings shed light on potential mechanisms underlying students' online engagement and offer practical recommendations for instructors to enhance their pedagogical strategies when using Zoom and other online learning platforms. In Study 2, I expand on the insights from Study 1 to redesign an undergraduate biology course with the LXD paradigm, utilizing 4k videography, customized dashboards, and user experience design. Through in situ Design-Based Research (DBR) and mixed-methods analysis (n = 181), the results highlight the impacts of self-efficacy, task-value, and self-regulation significantly predicting higher levels of student engagement, elaboration, and critical thinking, further corroborated by qualitative analysis showing the positive effects of LXD interventions on student motivation and learning experiences. This research significantly contributes to STEM online teaching and learning in higher education, advocating for the thoughtful deployment of LXD strategies. In Study 3, I address the opportunities and challenges highlighted in Study 2 and expand upon these findings by conducting a quasi-experimental investigation. As such, I delve into the efficacy of interactive embedded video questions in enhancing students' learning outcomes in a second iteration of the same asynchronous biology course. Guided by LXD principles, these questions aim to leverage the testing effect on students' retrieval and conceptual understanding by prompting learners to answer low-stakes questions while watching course videos. The results from the two treatment conditions (n = 92 for "delayed" and n = 91 for "immediate") indicate significant differences in low-stakes question accuracy, summative quiz scores, engagement, mind-wandering, self-regulation, and cognitive load, with the effects being more pronounced for students in the immediate condition. Overall, my dissertation underscores the importance of adapting pedagogical strategies to meet the evolving needs of learners in higher education with a human-centered empathetic approach. Through rigorous empirical research, it provides invaluable insights and practical recommendations for educators striving to optimize the online learning experiences of their students. [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.]