This volume of the revised edition describes and evaluates measurement methods, research designs, and procedures which have been or might appropriately be used in self-concept research. Working from the perspective that self-concept or phenomenal personality theories can be scientifically investigated, methodological flaws and questionable practices are summarized, and problems of operationally defining self-concept variables are considered. Thirteen instruments, representing both those which explicitly purport to index the phenomenal self-concept and those without explicit reference to the conscious-unconscious dimension, are described and evaluated. The measurement of the unconscious self-concept and the empirical study of the "insightfulness" of the conscious self-concept are examined. The concluding chapter presents an appraisal of the main conceptual and methodological implications of the detailed facts and evaluations offered in this volume. (BW)