Does enough evidence exist to modify Holland's theory to accommodate the individual differences of diverse populations?

The research by Fouad and Dancer, Swanson, and Prediger and Vansickle-each using an impressive data set and a rigorous research design-contributes to the existing literature on the structure of interests. Fouad and Dancer and Swanson's results provide evidence that the Holland RIASEC-order hypothesis is robust across cultures. Analogous to the construct of values, the construct of interests appears to have a broad pattern of structural similarity across cultures in concert with specific sample differences that reflect the individual differences of cultures. These specific sample differences call into question the calculus assumption on which Holland's congruence construct is based. Prediger and Vansickle's Hexagon Congruence Index, however, may offer an alternative to existing methods of congruence assessment that circumvents the calculus assumption.