The purpose of this study is (1) to determine the fundamental differences in the American Federation of Teachers and the National Education Association and (2) to evaluate these organizations in terms of criteria basic to the organization of any group. It is hoped that a microscopic analysis and evaluation of these two teacher organizations, representing both union and non-union groups, will cast some beneficial light upon weaknesses and strong points of both groups and result in recommendations which will be of benefit in the work of individual teachers as well as to the organizations.