نسیم قنبری

This study examined the language achievement of learners at different ability levels in two heterogeneous and homogenous cooperative learning (CL) groupings. Furthermore, the study explored the perceptions of the learners involved in either grouping. For this aim, a body of 100 intermediate EFL learners was randomly assigned to either homogeneous or heterogeneous groups. The treatment lasted nine weeks of instruction. Upon the end of treatment sessions, results of T-Tests showed that while high and average learners substantially benefited from homogeneous grouping, low achievers did equally well in either groups. Also, learners' interview statements revealed that while they envisaged CL as a beneficial pedagogic technique in the class, there were considerable differences in the way they perceived the two groupings. Findings suggest that despite the common practice of heterogeneous grouping, there was no solid empirical basis for its superiority compared with the homogeneous grouping in this particular EFL context.