“…These findings validate the extensive review of 323 studies yielding 1,691 findings conducted by Johnson & Johnson (2002), which reported that students in cooperative situations academically outperformed students in individualistic settings (effect-size = 0.75). Similar findings have also been noted in recent studies (Yamarik, 2007;Kilic, 2008;Doymus, 2008a&b;Adeyemi, 2008;Sahin, 2010;Doymus, Karacop & Simsek, 2010;Bertucci, Conte, Johnson, & Johnson, 2010;Slavin, 2011) which report that students in CL groups have higher adjusted posttest mean scores than those in conventional lecture groups. The findings of the above research studies have led to strong arguments by various authors that CL is an effective teaching pedagogy for schools.…”