Unique data containing coursework-mastery test scores for all middle school students in a large urban school district are employed to test the narrowly defined meritocratic hypothesis that course-grade differentials for gender, ethnicity, and poverty groups are accounted for by the differential coursework mastery of these groups. A broadly defined meritocratic hypothesis is also tested by a model which includes measures of student absenteeism as well as 'frog pond" and "bad school" contextual effects. Both the narrowly and broadly defined meritocratic hypotheses are rejected. With coursework mastery and the other variables held constant it is found that girls receive higher course grades than boys, Asians receive higher course grades than Anglos, and nonpoor youths receive higher course grades than poor youths. Black/Anglo and Hispanic/Anglo differentials are mixed. Implications are drawn for future studies of the educational stratification process. GEORGE FARKAS is a professor of sociology and political economy at the School of Social Sciences, University of Texas at Dallas, Richardson, TX 75080. He specializes in the sociology of education. DANIEL SHEEHAN is principal evaluator for test development at the Department of Planning, Evaluation, and Testing, Dallas Independent School District, 3801 Herschel, Dallas, TX 75219. He specializes in psychometrics. ROBERT P. GROBE is an administrator for research and evaluation at the Mt. Diablo Unified School District, 1936 Carlotta Dr., Concord, CA 94519-1397. He specializes in educational research. at MOUNT ALLISON UNIV on June 9, 2015 http://aerj.aera.net Downloaded fromFarkas, Sheehan, and Grobe S tudies of the role of education in the socioeconomic attainment process have long sought to measure that portion of the attainment process directly attributable to cognitive skills and performance. A "meritocratic debate" has dominated discussions of this research. Thus, examinations of the process of attainment during the school years have focused on the extent to which course grades and course placement (curriculum tracking) are determined by coursework mastery or are ascribed on the basis of student characteristics, such as social class background, ethnicity, gender, and their correlates (Sexton).The long duration and continued inconclusiveness of this debate are due to both conceptual and methodological problems. In the studies cited there has been a scarcity of data sets containing reliable and valid measures of actual performance in learning assigned coursework. As a consequence, investigators have resorted to standardized achievement or "ability" test scores whose relationship to coursework mastery is at best problematic. Even where data collection efforts have included tests of substantive knowledge, as in the recent national High School and Beyond study, these are based on relatively few items and cannot be expected to correctly represent the different curricula in use across the country. 1 Popham (1978) discussed the weaknesses of standardized achievement tests as ...