Table 4 Data sources and data integration

Observation

Frequency

Publications

Multiple data sources, same format

14

Lopez Guarin et al. (2015), Park et al. (2016), Di Mitri et al. (2017), Rodríguez-Triana et al. (2018), Liu et al. (2017), Gray et al. (2016), Hutt et al. (2017), Jayaprakash et al. (2014), Raca et al. (2016), Mangaroska et al. (2019), Villano et al. (2018), Sandoval et al. (2018), Sun et al. (2018), Giannakos et al. (2019)

Multiple data sources, different formats

6

Thompson et al. (2014), Zheng et al. (2017), Pardos and Kao (2015), Ochoa et al. (2018), Wang et al. (2014), Wong et al. (2018)

Support educational data specifications

3

Pardos and Kao (2015), Di Mitri et al. (2017), Mangaroska et al. (2019)