Designed to complete a cycle begun in 1946, the 1950 Service-Wide Testing Program examined: the progress and achievement made by American Indian students in various educational situations, and the factors thought to affect their educational development. Tests were administered to all students in grades 8 and 12 enrolled in day, mission, public, nonreservation boarding, and reservation boarding schools located in nine geographic areas--Alaska, Dakota, Mountain, Navajo, Oklahoma, Pacific, Pueblo, Southeast, and Southwest. The tests included: Pressey Diagnostic Reading, Grades 3-9, Form a; Arithmetic-Factor Abilities, Form usis--fa-a-1-47; Free Writing Test, Form c, usis--fwa-c-48; Use of Resources--USIS-3-46; Pressey English, Grades 5-8; Gates Basic Reading, Grades 3-8; Orleans Arithmetic Computation, Form I, Grades 3-8; and Health and Safety--USIS-HS-A-47. These tests were not all administered in both grades. The mean, standard deviation, plus one standard deviation, and minus one standard deviation were calculated for 360 distributions. Data were also obtained on the student's degree of Indian blood, language spoken at home, home stability, place of residence, kinds of friends, late entrance to school, size of school attended, regularity of school attendance, and academic ambition. It was found that as the cultural and educational backgrounds of Indian children became more like those of white children in the public schools, the educational achievement of Indian children matched that of white children more closely.