“…Indeed, empirical evidence suggests that grouping influences the degree to which different achievers (low, average, high) respond and participate within a group (Saleh, Lazonder, & De Jong, 2005;Webb, 1991). For instance, low-ability students perform well in heterogeneous groups in which they have the possibility of interacting with more competent individuals, asking questions, receiving explanations, and filling in the gaps in their knowledge (Lou et al, 1996;Hooper & Hannafin, 1991). As far as students with high ability are concerned, they can benefit from both heterogeneous and homogenous groups (Lou et al, 1996;Saleh et al, 2005).…”