built on the assumption that there are only six kinds of people in the world is unacceptable on the strength of common sense alone. But a six category scheme that allows a simple ordering of a person's resemblance to each of the six models provides the possibility of 720 different personality patterns." Related model Prediger's two-dimensional model Prediger constructed the scale of "work task" and "work relevant abilities" based on Holland's model, and carried out factor analysis and multidimensional scale analysis to clarify the basic structure. As a result, two axes of Data/Ideas and Things/People were extracted. Although Prediger's inquiry did not start from interest per se, it eventually led to the birth of models other than RIASEC, suggesting that the structure of occupational interest may provide a basic dimension. Tracey and Rounds's octagonal model In the United States, the energetic trial is being made with the aim of the new model which surpasses Holland hexagon model in 1990's. Tracey & Rounds's octagonal model is one such example. Based on the empirical data, they argue that occupational interests can be placed circularly in a two-dimensional plane consisting of People/Things and Data/ldeas axes, and the number of regions can be arbitrarily determined. According to their model, only Holland's hexagonal model does not adequately represent the structure of occupational interest, and it is possible to retain validity as an octagonal or 16 square model if necessary. Tracey, Watanabe, & Schneider conducted an international comparative study of job interests among Japanese and U.S. university students, and the results suggest that the Tracey & Rounds's octagonal model is more fitted to Japanese students than Holland's hexagonal model. Tracey and Rounds's spherical model Tracey & Rounds criticizes that the conventional models of occupational interest structure do not correctly depict the positional relationship of occupations because they neglect occupational prestige, i.e., "social prestige" or "high socioeconomic status" and proposes a spherical model that assigns occupations to a 3-dimensional space incorporating occupational prestige. In this model, 18 regions of interest are displayed on a spherical space. The left hemisphere has a high status area, with Health Sciences at the top. The right hemisphere has a low status area, with Service Provision as the lowest ground. Though this model is excellent in the point of more accurately describing the relation between various occupations, it makes the occupation interest structure more complicated, and there is a weak point that