The data on years of school completed were derived from the answers to the two questions: (a) What is the highest grade (or year) of regular school he has ever attended? and (b) Did he finish this grade (or year)? Enumerators were instructed to obtain the approximate equivalent grade in the American school system for persons whose highest grade of attendance was in a foreign school system, whose highest (Note: the text in the original document is not clearly visible) graded school, whose highest level of schooling was measured by readers, or whose training by a tutor was regarded as qualifying under the regular school definition. Persons were to answer NOto the second question if they were attending school, had completed only part of a grade before they dropped out, or failed to pass the last grade attended.

The three major race categories distinguished in this report are white, Negro, and other races. Among persons of other races are American Indians, Japanese, Chinese, Filipinos, Koreans, Asian Indians, and Malayans. Negroes and persons of other races taken together constitute nonwhite persons. Persons of Mexican birth or descent who are not definitely Indian or other nonwhite race are classified as white. In addition to persons of Negro and of mixed Negro and white descent, the category Negro includes persons of mixed Indian and Negro descent unless the Indian ancestry very definitely predominates or unless the person is regarded as an Indian in the community.