Sociological interpretations of racial and ethnic relations in modern industrialized societies are examined. Ethnic and racial relations are interpreted as areas of study within the discipline of sociology which focus on interaction of ethnic and/or racial aims and demands with social processes and cultural phenomena. To clarify the state of the art of ethnic relations and ethnicity, researchers should determine recurring research problems and ascertain how to make research in ethnic relations more valid. Major problems with existing research include that it excludes important conditions, variables, and contexts; overemphasizes concepts; underemphasizes income and power; hasn't updated concepts so that they apply to present conditions; and defines conceptual schemes too narrowly. Researchers can correct these and other faults if they devise appropriate conceptualizations which are in line with systematic comparative data, move away from ad hoc descriptions and toward well-defined variables which will serve to characterize recurrent situations, and stress historical and cross-cultural documentation. The conclusions are that ethnicity is a major factor in political and social change in modern as well as developing societies and that researchers must update their methods so that they can realistically interpret data relating to ethnic groups, ethnic relations, and ethnicity. (DB)