“…For example, it is reported that there was a lack of computer labs, computers, electricity outages (Wijekumar et al, 2013 ), high quality video equipment (Roll et al, 2011 ) or learning systems (Mousavi et al, 2021 ). In addition, there can be limited data access (Hickey et al, 2020 ; Butcher & Aleven, 2013 ; Jiang et al, 2020 ), and no sufficient resources for one-on-one tutoring (Ward et al, 2011 ), applying randomized assignment (Treceño-Fernández et al, 2020 ; Hickey et al, 2020 ), and keeping intervention dosage (Nye et al, 2018 ), grading scheme, and the number of benchmarks (Cung et al, 2019 ) consistent during the study. Additionally, in some studies, the participants did not have the necessary skills (e.g., keyboarding, Baker et al, 2020 ) to manage and use ITSs.…”