In order for ethnic identity to develop as a methodologically sound area of psychological research, it is essential to agree on definitions and to develop and validate measures that can be used in common by researchers working with different groups. This report analyzes 62 empirical studies of ethnic identity published in 36 journals since 1972. The following topics are discussed: (1) the assessment of the components of ethnic identity; (2) the structure of ethnic identity; (3) the relationship of ethnic identity to the majority culture; (4) the study of changes in ethnic identity over time and context; and (5) the personal implications of ethnic identity. The following theories appear to form the conceptual bases of about one-third of the studies reviewed: (1) social identity theory; (2) social field theory; (3) acculturation and assimilation theory; (4) Erikson's ideas on identity development and the impact of social and cultural factors; (5) psychoanalytic identity formation theory; and (6) black identity development theory. Definitions of the following concepts are suggested: (1) ethnic identity; (2) identification; (3) self-identification; (4) ethnicity; (5) ethnic attitudes; (6) ethnic behaviors; and (7) ethnic identity development. Common measurement techniques are discussed in relation to a suggested conceptual model and directions for future research are suggested. Two charts and a list of 94 references are appended. (FMW)