Try Wonders for freeHow the literature is organised
There are three layers. The oldest is distance education, a field with its own theory and journals. Garrison, Anderson and Archer (2001) belongs here: they operationalise cognitive presence through a practical inquiry model and argue it can be created in a computer-conference environment given appropriate teaching and social presence. So does Anderson (2008), The Theory and Practice of Online Learning, an open textbook from Athabasca University released under a Creative Commons licence and therefore free to read. Bernard et al. (2004) meta-analysed 232 comparative studies with 688 outcomes and found effect sizes essentially zero on achievement, attitude and retention, with wide variation: synchronous distance education tended to favour the classroom, asynchronous distance education tended to favour distance.
The second layer is e-learning in the 2000s. Sun et al. (2008) modelled the critical factors behind learner satisfaction. Ruiz, Mintzer and Leipzig (2006) concluded that in diverse medical education contexts e-learning appears at least as effective as instructor-led methods such as lectures, and that students saw it as a complement rather than a replacement.
The third layer is the pandemic. Dhawan (2020), a SWOC analysis of e-learning written from India in the first months of the crisis, is the most-cited work on this page, and much of the recent list consists of surveys of students' experiences in 2020 and 2021.
Main debates
The key conceptual argument is whether pandemic teaching tells us anything about online learning at all. Adedoyin and Soykan (2023) describe what happened as crisis-response migration and state that online learning is different from emergency remote teaching; Bozkurt and Sharma (2020) is the editorial that put the second term into wide circulation. If you cite pandemic-era satisfaction surveys as evidence about online learning in general, expect a reviewer to raise this.
A second debate concerns access, and the listed studies from lower- and middle-income settings are specific about it. Adnan (2020) reports that a large majority of Pakistani students surveyed could not get online for technical and monetary reasons. Muthuprasad et al. (2021) found Indian agricultural students mostly using smartphones, with rural broadband the limiting factor, and practical courses ill-suited to a fully online mode. Barrot et al. (2021) found that the greatest challenge for Philippine college students was their learning environment at home, and the least was their own technological literacy. Salas-Pilco, Yang and Zhang (2022), reviewing Latin American higher education, put improving internet connectivity among their five implications for policy.
Where recent work is heading
Attention has moved to what makes online study work for the individual. Chiu (2022) applied self-determination theory to 1,201 Grade 8 and 9 students and found all three psychological needs predicting engagement, with support for relatedness particularly important. Seo et al. (2021) interviewed 12 students and 11 instructors about AI in online courses and found the same systems seen as enabling personalised interaction at scale and as risking social boundaries, with concerns about responsibility, agency and surveillance.
Recent reviews cover adaptive learning using AI (Gligorea et al., 2023, across 63 articles), automatic feedback (Cavalcanti et al., 2021, who report that 65% of studies found automatic feedback improved student performance but found no evidence it eased instructors' workload) and gamified e-learning (Saleem, Noori and Ozdamli, 2022; Khaldi, Bouzidi and Nader, 2023, who note that only 9 of 39 primary studies were underpinned by motivational theory). Müller and Mildenberger (2021) meta-analysed 21 effect sizes and found that replacing 30% to 79% of classroom time with online learning produced equivalent learning outcomes. García-Morales, Garrido-Moreno and Martín-Rojas (2021) discuss the longer-term transformation of higher education after the disruption.