“…A circle, of course, is two-dimensional, thus suggesting that there are two basic dimensions on which occupations differ. Although Roe [10] and, more recently, Roe and Klos [11] speculated on the nature of these dimensions, no attention has been given to this question in Holland's theory or occupational classification system [8]. Figure 1 shows the general configuration of the Roe and Holland occupational clusters and related clusters in the ACT-OCS.…”