The COVID-19 pandemic forced a rapid shift to online learning globally, impacting nearly all students. While substantial research exists on the immediate impact of this shift, a gap remains in understanding the retrospective perspectives of both undergraduates and instructors. This study aims to address this gap by exploring the effectiveness of online learning from both student and instructor viewpoints in a Chinese university. The research employs a framework of nine factors: behavioral intention, instruction, engagement, interaction, motivation, self-efficacy, performance, satisfaction, and self-regulation. The study seeks to answer three research questions: 1. How do undergraduates and teachers in China retrospectively perceive the effectiveness of online learning after the COVID-19 pandemic? 2. Which of the nine outcome influencing factors had the most significant impact on online learning experiences after the pandemic, and why? 3. What recommendations can be proposed to enhance the effectiveness of online learning in the future? The study's findings are crucial for informing educational policies and improving online learning strategies, particularly given the increasing prevalence of digital learning environments.

Existing literature on online learning reveals mixed results, with some studies highlighting its effectiveness in terms of improved outcomes, flexibility, and enhanced digital skills, while others emphasize challenges such as the digital divide, motivational issues, engagement concerns, and the need for effective instructional practices. Research has focused on various aspects of online learning, including student experiences, technological aspects, pedagogical strategies, and socio-emotional factors. However, there's a lack of comprehensive frameworks incorporating multiple factors and a scarcity of studies examining long-term retrospective perspectives of both students and instructors. This study addresses this gap by utilizing a framework that includes student engagement, instructional design, technology infrastructure, student-teacher interaction, and student self-regulation as key determinants of online learning outcomes. The literature also shows that students appreciate the flexibility of online learning but struggle with motivation, technical issues, and a lack of interaction. Teachers, too, face challenges in online instruction, including technological issues, course design, and maintaining student engagement.

This study employed a qualitative research design using reflective diaries and interviews. Participants included 46 first-year undergraduate students and 18 experienced teachers from a comprehensive university in China. Convenience sampling was used to ensure diversity across academic disciplines. Students maintained reflective diaries for one semester, responding to four questions about their online learning experiences. These questions probed their attitudes, identified problems and shortcomings, explored reasons for these problems, and proposed improvements. Teachers were interviewed using the same four questions. Thematic analysis was employed to analyze the data, guided by the nine-factor framework. The analysis involved familiarizing oneself with the data, generating initial codes, searching for themes, defining and naming themes, and validating findings through peer debriefing and member checking. An audit trail was maintained throughout the process.

Thematic analysis based on the nine factors revealed that "instruction" was the most significant factor for both students and teachers, followed by engagement, self-regulation, interaction, and motivation. However, the specific aspects of instruction considered most important differed. Teachers highlighted technological challenges, while students focused on engaging content and teaching methods. Students' perspectives revealed significant challenges with self-regulation, distractions, and the need for stronger instructor supervision and support. The study also found a divergence between students and teachers concerning self-efficacy and self-regulation. Teachers emphasized self-efficacy of students, while students focused more on the need for effective self-regulation strategies. Students often lacked the independent learning skills required for optimal success in an online environment. Students' satisfaction was influenced by factors such as the perceived quality of instruction and the level of engagement they experienced, highlighting the importance of teacher's role in improving online learning. The analysis of participants' responses, categorized into positive, neutral, and negative attitude groups, provided a more nuanced understanding of the perceived disadvantages of online learning and how these attitudes shape perceptions of self-regulation and other related factors.

The findings highlight the critical role of instruction in successful online learning, but also reveal significant differences in the perceptions of students and teachers regarding the nature of effective instruction. The high emphasis placed on instruction by students suggests that they did not fully embrace self-directed learning. The study underscores the need for a holistic approach that supports both student autonomy and instructor guidance. The identified challenges with self-regulation and engagement further emphasize the necessity of providing students with the necessary skills and support to thrive in online learning environments. The divergence in perspectives between students and instructors indicates the need for improved communication and collaboration to create more effective online learning experiences. The results are consistent with other research that highlights the importance of engagement, interaction, and self-regulation in online learning, and the need for instructors to adapt their teaching to the unique challenges of online instruction.

This study provides valuable insights into the retrospective perceptions of online learning effectiveness among students and instructors. Instruction was consistently identified as the most critical factor, followed by engagement and self-regulation. However, significant differences in perspective exist between students and instructors. The study highlights the need for a more balanced approach to online learning, supporting both student autonomy and instructor guidance. Future research should focus on larger, more diverse samples, explore the interrelationships between the nine factors, and investigate strategies for improving students' self-regulated learning skills.

The study's limitations include its reliance on a single research method (reflective diaries and interviews) and a relatively small sample size from a single university in China. This may limit the generalizability of the findings to other contexts and populations. Future research should use mixed methods and include larger, more diverse samples to strengthen the generalizability and validity of the findings. The convenience sampling may also introduce bias, as participants may not be fully representative of all students and instructors.