Schools’ Role in Achievement Gaps Scrutinized

Two new studies shed light on how the achievement gaps between groups of students grow as they move from elementary to middle school.

The studies—one by researchers Eric A. Hanushek and Steven G. Rivkin and the other by the Northwest Evaluation Association—both found that black students start out school trailing behind their white counterparts, learn less over the course of the school year, and fall further behind as they progress through school.

But the studies diverge as they try to pinpoint potential causes...