| Barriers to online learning | Studies |
| Adjustment to the online learning style, distractions in the environment, engagement during online classes, Issues with concentration during online classes. | Baticulon et al. (2021), Anastasakis, Triantafyllou, and Petridis (2021), Islam and Habib (2021), Roslan and Halim (2021), Kara (2021). |
| Balance with family responsibilities, family distraction. | Baticulon et al. (2021), Van and Thi (2021), Islam and Habib (2021), Kara (2021). |
| Technological infrastructure. | Aljaraideh and Bataineh (2019), Roslan and Halim (2021). |
| Lack of social interaction. | Van and Thi (2021), Anastasakis, Triantafyllou, and Petridis (2021), Islam and Habib (2021), Muilenbug and Berge (2005), Kara (2021). |
| Internet-related issue. | Van and Thi (2021), Octaberlina and Muslimin (2020), Anastasakis, Triantafyllou, and Petridis (2021), Islam and Habib (2021), Muilenbug and Berge (2005), Roslan and Halim (2021), Roslan and Halim (2021). |
| Learner motivation. | Van and Thi (2021). |
| Unfamiliar with e-learning, technological skills. | Octaberlina and Muslimin (2020), Islam and Habib (2021), Muilenbug and Berge (2005). |
| Physical conditions such as eye strain. | Octaberlina and Muslimin (2020). |
| Teacher online teaching skills. | Anastasakis, Triantafyllou, and Petridis (2021), Baticulon et al. (2021), Roslan and Halim (2021), Roslan and Halim (2021), Kara (2021). |
| Administrative issue. | Anastasakis, Triantafyllou, and Petridis (2021), Muilenbug and Berge (2005). |
| The appropriateness of course content for online delivery. | Anastasakis, Triantafyllou, and Petridis (2021), Roslan and Halim (2021). |
| Learners’ characteristics (i.e. Time management, shyness, and disability), laziness, low motivation, anxious. | Anastasakis, Triantafyllou, and Petridis (2021), Islam and Habib (2021), Muilenbug and Berge (2005), Roslan and Halim (2021). |
| Financial hardship. | Islam and Habib (2021). |
| Difficult to understand. | Islam and Habib (2021). |
| Lack of support. | Islam and Habib (2021), Kara (2021). |
| Increased workload. | Islam and Habib (2021), Roslan and Halim (2021). |
| Hard to submit assignments online. | Islam and Habib (2021), Roslan and Halim (2021). |
| Difficult to participate in online exam. | Islam and Habib (2021), Roslan and Halim (2021). |
| Lack of resources for online learning. | Bates (2017). |
| Lack of online learning specialist. | Bates (2017). |