“…Approximately half of the empirical research articles (n = 51, 48%) applied spaced learning in an online setting, mostly through delivering learning sessions in e-mails distributed over time using electronic modules, eg, Qstream [19][20][21]23,[27][28][29][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]47,[51][52][53][54][55]64,74,[78][79][80][81][82][83][84][85] (n = 38, 37%). Spaced learning was also implemented in simulation settings 46,48,53,56,65,67,68,75,76,[86][87][88]…”