... Out of 13 analyzed articles 5 were group study design (Pan, 2010;Fragala -Pinkham, Haley, & O'Neil, 2011;Pan, 2011;Chu & Pan, 2012;Lawson, Foster, Harrington, & Oxley, 2014), and another 8 were single subject design (Huettig & Darden-Melton, 2004;Yilmaz, anardag, irkan, & umin, 200 ;ilmaz, irkan, onukman, & Erkan, 200 ; lmaz, onukman, irkan, zen, anardag, & C amursoy, 2010a; lmaz, onukman, Birkan, & Yanardag, 2010b, Rogers, Hemmeter, & Wolery, 2010Ennis, 2011;Yanardag, Akmanoglu, & Yilmaz, 2013). The total number of participants in all studies was 167, where Yilmaz et al. (2004) had the lowest number of participants, at 1, while Chu et al. (2012) and Lawson et al. (2014) had the highest number of participants, at 42. ...