AN ANALYTIC EMPIRICAL APPROACH TO THE STUDY OF MEXICANS IN THE UNITED STATES IS PRESENTED. MEXICAN-AMERICANS FORM AN IMPORTANT ETHNIC GROUP BY VIRTUE OF NUMBERS, REGIONAL CONCENTRATION, SOCIAL POSITION, AND DYNAMIC CHARACTER. FINDINGS SHOULD BE AMENABLE TO COMPARATIVE TREATMENT WITH OTHER STATUS AND ETHNIC GROUPS. THE APPROACH INVOLVES A SERIES OF RESEARCH TASKS. THE FIRST SET CENTERS ON DIFFERENTIATING THE POPULATION WITH REGARD TO ITS SOURCES AND MIGRATION HISTORY. GEOGRAPHIC ORIGINS AND PRIOR OCCUPATIONAL AND STATUS CHARACTERISTICS, WITH SPECIAL REFERENCE TO THE DEGREE OF INDUSTRIALIZATION AND URBANIZATION IN MEXICO AND ACCULTURATION TO HISPANIC NORMS, ARE CONSIDERED. RELATED ARE THE NATURE AND CONSEQUENCES OF INTERNAL MIGRATIONS, BOTH IN MEXICO AND IN THE UNITED STATES. THE SECOND FOCUS INVOLVES THE DIFFERENTIATION OF THE POPULATION ACCORDING TO ITS CURRENT SOCIOECONOMIC STATUS, URBANIZATION, AND ACCULTURATION TO AMERICAN NORMS. OBJECTIVE INDICES SHOULD BE APPROPRIATE TO THE RANGE OF VARIATION FOUND IN THE POPULATION STUDIED. THE THIRD TASK IS A DETERMINATION OF THE WAYS IN WHICH ESTABLISHED DIFFERENTIALS OPERATE TO PRODUCE VARYING MODES OF CULTURAL AND INSTITUTIONAL ISOLATION OR FUNCTIONAL INTEGRATION. THREE PATTERNS OF DEVELOPMENT ARE POSSIBLE IN THE FUTURE--THE CONTINUED ISOLATION OF RELATIVELY SMALL HOMOGENEOUS GROUPS MARGINAL TO BUT DEPENEDENT ON URBAN CENTERS, THE EMERGENCE OF AN INTEGRATED ETHNIC COMMUNITY, OR THE INCORPORATION OF THE MEXICAN-AMERICAN POPULATION INTO THE GENERAL SOCIETY.