Abstract Preschoolers' cognitive abilities were assessed each year as part of the Head Start Program requirements. The Head Start PK-4 Center evaluated preschoolers' cognition by administering the Learning Accomplishment Profile-Diagnostic (LAP-D), as a pretest and posttest measure. The LAP-D study used archival data collected from the 2009-2010…

By using a quasi-experimental design, in this study, we test the effect of undergraduate teaching assistants on student learning. Data were collected from 170 students enrolled in four sections of a quantitative research methods course, two sections without undergraduate teaching assistants and two sections with undergraduate teaching assistants,…

In light of rapid demographic shifts and legal challenges to affirmative action in the United States, the issue of diversity on college campuses is of increasing importance. Most syntheses of research on diversity interactions and educational outcomes have focused on attitude change, such as reductions in prejudice or racial bias. Despite the…

The author refutes Humphrey's test of the Spearman hypothesis. A fair test requires that Black and White samples not be selected on any g-correlated variable, including socioeconomic status. Humphrey's factor analysis on test-score means of demographic groups, rather than on individuals, inflates g loadings and biases results. (LMO)

This author reviews published data and presents new data relevant to the Spearman hypothesis concerning racial differences on cognitive tests. He concludes that across-the-board difference between SES groups occurs primarily on the general factor, and that there are major determinants of race differences independent of the general factor.…

The author responds to criticisms made by Jensen pertaining to tests of the Spearman hypothesis. The near-zero correlation between Blacks and low socio-economic status Whites is neither an artifact of methodology nor a sampling fluke. Low and high SES White differences are highly correlated with general factor loadings. (LMO)