Table 6. Classification of types of research.

Types	Studies
Model	Liao et al., 2019; Bhatia, Kohli & Singh, 2018; Ninrutsirikun et al., 2020; Effenberger, Pelánek & Čechák, 2020; Iqbal Malik & Coldwell-Neilson, 2017; Ashenafi, Riccardi & Ronchetti, 2015; Carter, Hundhausen & Adesope, 2015
Framework	Yeomans, Zschaler & Coate, 2019; Chaweewan et al., 2018; Omer, Farooq & Abid, 2020; Premchaiswadi, Porouhan & Premchaiswadi, 2018
Experiment	McCall & Kölling, 2019; Ullah et al., 2019; Ureel & Wallace, 2019; Pereira et al., 2020; Esteero et al., 2018; Gomes & Correia, 2018; King, 2018; Lin et al., 2018; Turner, Pérez-Quiñones & Edwards, 2018; Ahadi, Hellas & Lister, 2017; Ahmad et al., 2017; Delev & Gjorgjevikj, 2017; Dorodchi, Dehbozorgi & Frevert, 2017; Echeverría et al., 2017; España-Boquera et al., 2017; Estey, Keuning & Coady, 2017; Chung & Hsiao, 2020; Fu et al., 2017; Hsiao, Huang & Murphy, 2017; Kumar, 2017; Seanosky et al., 2017; Berges et al., 2016; Funabiki, Ishihara & Kao, 2016; Gomes, Correia & Abreu, 2016; Malliarakis, Satratzemi & Xinogalos, 2016; Zur & Vilner, 2014; Seeling, 2016; Ahadi et al., 2015; Rubio et al., 2014; Rosiene & Rosiene, 2015; Scott et al., 2015; Ureel & Wallace, 2015; Wood & Keen, 2015; Xinogalos, 2015; Allinjawi, Al-Nuaim & Krause, 2014; Doshi, Christian & Trivedi, 2014; Edwards, Shams & Estep, 2014; Edwards, Tilden & Allevato, 2014; Heinonen et al., 2014
Improvement	Azcona, Hsiao & Smeaton, 2018; Koong et al., 2018; Lagus et al., 2018; Carter, Hundhausen & Adesope, 2017; Castro-Wunsch, Ahadi & Petersen, 2017; Su et al., 2015; Hijon-Neira et al., 2014
Case study	Albluwi, 2018; Santana, Figueredo & Bittencourt, 2018; al-Rifaie, Yee-King & d’Inverno, 2017; Simkins & Decker, 2016; Janke, Brune & Wagner, 2015
Evaluation	Wainer & Xavier, 2018; Seeling & Eickholt, 2017; Watson, Li & Godwin, 2014; Hilton & Rague, 2015