This from Education Week:
Outcomes for students varied by techniques used in their groups.
White and African-American students can perform dramatically differently in the classroom, depending on how their teachers structure their learning groups, a new study suggests.
Published last month in the peer-reviewed journal Cognition and Instruction, the study is the latest in a growing line of research to explore the role that students’ home cultures and experiences outside of school play in the classroom.
Studies also have long shown that students of all races—but African-American students, in particular—often perform better in cooperative-learning groups...
...While all of the racial groups in the study by [Eric A.] Hurley and his co-authors performed about the same, overall, on a math-estimation test taken after the group lessons, the researchers found some marked differences when students of different racial groups worked under different group conditions.
The black students scored highest—getting 9.63 out of 15 questions correct—after having taken part in the “communal” group lessons. They turned in their worst group performance following their time in the group that emphasized individual rewards, answering only 6.41 of 15 questions correctly.
The individual-reward group, on the other hand, turned out to be the most optimal setting for white students, as a group, with white students getting 10.19 of those questions correct. In comparison, the white students got only 6.72 right answers—their worst performance—following lessons in the “communal” group....