Black, Alison Rebeck Using covariates to improve precision for studies that randomize schools to evaluate educational interventions pp. 30-59 Howard S. Bloom, Lashawn Richburg-Hayes, and Alison Rebeck Black Educational evaluation and policy analysis Vol. 29 No. 1 Mr 2007 A Quarterly publication of the American Educational Research Association Subjects--Uniform Titles: RANDOMIZING SCHOOLSCLUSTER RANDOMIZATIONPRECISIONSTUDENT ACHIEVEMENTINTRACLASS CORRELATIONEDUCATIONAL INTERVENTIONSPRETESTS LC Class. No.: JNF LB 1028 E35 2007