The purpose of the study was to investigate whether selected test and item characteristics in the Scholastic Aptitude Test (SAT) are associated with unexpected differential item functioning (DIF) for males and females and for majority and minority group members (i.e., White performance compared with Black, Asian American, Hispanic American, and American Indian performance). Six forms of the SAT, with 379,896 examinees in all, each containing verbal and mathematics sections and the Test of Standard Written English (TSWE), were used. Findings from previous studies, test specifications, and suggestions from experts led to the identification of more than 100 a priori item coding categories. Each SAT item was coded accordingly, by type, content, and format. The Mantel-Haenszel procedure was used to provide an index of DIF for each reference (males and Whites) and focal group (females and ethnic groups other than White) comparison. The study identifies and reports on patterns of differential performance and section-specific differences for gender and ethnic groups. Three appendixes contain the coding categories for verbal and mathematics sections and the TSWE. Study findings are reported in 38 tables. (Contains 29 references.) (SLD)