Essays on user behavior in online platforms

Abstract

In this dissertation, I investigate user behavior in two different domains: online shopping and online learning. The first essay examines the provision of helpful product video reviews. As the provision of online review videos grows and consumers increasingly rely on them for their purchase decisions, understanding factors that contribute to the perceived helpfulness of video reviews becomes critical for video review management. I find that video viewers perceive online product review videos that are more visually stimulating, more positive, and less subjective as more helpful. In addition, review videos are perceived as more helpful when reviewers reveal their faces in their reviews and when reviewers speak with faster speech rates and lower voice pitch. The second essay studies the dynamics of students’ online social engagement in the context of online learning and how the recent COVID-19 pandemic affected it. I propose a Hidden Markov Model (HMM) with students’ self-efficacy as hidden states to investigate the dynamics of elementary school students’ online social behavior. The result suggests that the amount of proactive social activities from teachers, peers, and parents have positive effects on students’ social engagement in any given self-efficacy state. The analysis on state transition suggests that the social influences from teachers, parents, and peers on students’ self-efficacy are positive for students with high self-efficacy. When students have lower self-efficacy, the peer influence on their self-efficacy is negative. However, the positive influences from teachers and parents can mitigate such negative peer influences. The results also imply that students’ self-observation of their past behavioral patterns positively affects their self-efficacy. Finally, the results suggest that the relative importance of parental influence and students’ personal influence increased during the pandemic. The reduced face-to-face schooling can explain such change during the pandemic.