Structural models divide the personality system and its associated traits into distinct areas. Four structural models are examined in regard to how well they do this. Three of the models—the trilogy of mind, Freud's structural model, and the recently introduced systems set—divide personality and its traits on conceptual bases. The last model, the 5-factor model, divides personality on an empirical basis. Two demonstration studies showed that expert judges who used the trilogy of mind and the systems set could reliably classify traits according to each set's conceptual divisions. The systems set provided a more reliable, comprehensive organization of traits than the trilogy of mind and generated a division of traits that contrasted provocatively with the 5-factor division.
