WITHIN-CLASS GROUPING - A METAANALYSIS

The effects of within-class grouping on student achievement and other outcomes were quantitatively integrated using two sets of study findin gs. The first set included 145 effect sizes and explored the effects o f grouping versus no grouping on several outcomes. Overall, the averag e achievement effect size was +0.17, favoring small-group learning. Th e second set included 20 effect sizes which directly compared the achi evement effects of homogeneous versus heterogeneous ability grouping. Overall, the results favored homogeneous grouping; the average effect size was +0.12. The variability in both sets of study findings was het erogeneous, and the effects were explored further. To be maximally eff ective, within-class grouping practices require the adaptation of inst ruction methods and materials for small-group learning.