Table 5 Game elements tested in the studies

Points only

1 (2%)

(Barrio et al., 2015)

Badges only

9 (18%)

(Boticki et al., 2015; Davis & Klein, 2015; Hakulinen et al., 2015; Leach et al., 2014; Long & Aleven, 2014; Pedro et al., 2015a; Perry, 2015; Tu et al., 2015; Tvarozek & Brza, 2014)

Leaderboards only

3 (6%)

(Christy & Fox, 2014; Landers & Landers, 2015; Poole et al., 2014)

PBL^a

14 (27%)

(Amriani et al., 2014; Anderson et al., 2015; Barata et al., 2014; Codish & Ravid, 2014; Hanus & Fox, 2015; Hew et al., 2016; Lambruschini & Pizarro, 2015; Laskowski & Badurowicz, 2014; Latulipe et al., 2015; Lehtonen et al., 2015; Nevin et al., 2014; Pedro et al., 2015b; Sillaots, 2015; Smith et al., 2014)

Others

24 (47%)

(Attali & Arieli-Attali, 2015; Auvinen et al., 2015, Bernik et al., 2015; Bonde et al., 2014; Boskic & Hu, 2015, Chang & Wei, 2015; Codish & Ravid, 2015; Hasegawa et al., 2015; Herbert et al., 2014; Holman et al., 2015; Ibanez et al., 2014; Jang et al., 2015; Knutas et al., 2014; Knutas et al., 2014; Krause et al., 2015; Mekler et al., 2015; Morschheuser et al., 2014; Paiva et al., 2015; Pettit et al., 2015; Shi et al., 2014; Sillaots, 2014; Smith et al., 2014; Su & Cheng, 2015; Utomo & Santoso, 2015)