It is argued that developmental psychology is the "third discipline of scientific psychology" , emphasizing the formal aspect of behavioral continuity/change. Constructs elaborating this aspect are semantical and not empty mathematical models or fuzzy common sense concepts. Assessment is comprehensively describcd as a matrix of four components (test theory, constructs, tests, diagnostica! proces) by three levels (common sense, scientific constructs, mathematical models). Developmental psychology and assessment are confronted to conquer and extend the meaning of continuity/change, as in "convergent" and "discriminant" construct validation. Test theory, tests and the diagnostica! proces respective! y offer models, instruments and a program for assessing behavior.

This is a review anide about the different theoretical positions on the Big Five dimensions of personality . This article presents the similarities and dilferences among the theoretical positions following a thorough reflection on the following topics: (a) the genesis of the content and structure of the Big Five; (b) the robustness of the five dimensions; (e) a description of the research on the relationship of the Big Five with other personality constructs; (d) a di~cussion about the predictive value of the Big Five profile scores for relevant criteria; (e) the theoretical status of the Five is analyzed; (f) historical criticisms on the Big Five are discussed; (g) sorne guesses for the future of the Five are put forward; and (h) conclusions and remarks about the Five dimensions of personality are drawn and made.

This is a review anide about the different theoretical positions on the Big Five dimensions of personality . This article presents the similarities and dilferences among the theoretical positions following a thorough reflection on the following topics: (a) the genesis of the content and structure of the Big Five; (b) the robustness of the five dimensions; (e) a description of the research on the relationship of the Big Five with other personality constructs; (d) a di~cussion about the predictive value of the Big Five profile scores for relevant criteria; (e) the theoretical status of the Five is analyzed; (f) historical criticisms on the Big Five are discussed; (g) sorne guesses for the future of the Five are put forward; and (h) conclusions and remarks about the Five dimensions of personality are drawn and made.

It is argued that developmental psychology is the "third discipline of scientific psychology" , emphasizing the formal aspect of behavioral continuity/change. Constructs elaborating this aspect are semantical and not empty mathematical models or fuzzy common sense concepts. Assessment is comprehensively describcd as a matrix of four components (test theory, constructs, tests, diagnostica! proces) by three levels (common sense, scientific constructs, mathematical models). Developmental psychology and assessment are confronted to conquer and extend the meaning of continuity/change, as in "convergent" and "discriminant" construct validation. Test theory, tests and the diagnostica! proces respective! y offer models, instruments and a program for assessing behavior.