“…ies of which the Spacing effect (n = 40) and Testing effect[19][20][21][22][23][24][25][26][27][29][30][31][32][33]37,39,[41][42][43][51][52][53]55,[58][59][60][61][62][63][64][65][66] (n = 31) were named most often.Other frameworks were Cognitive Load Theory 50,57,67,68 (n = 4), Desirable Difficulties Theory 59,69 (n = 2), Retrieval hypothesis70,71 (n = 2), Total-time hypothesis70,71 (n = 2), Learning Theory 72 (n = 1), Metacognitive Theory 73 (n = 1) and Kolb's Experiential Learning Theory 61 (n = 1).Only a few studies26,[31][32][33][34][39][40][41]56,60,64,69,[74]…”