The authors examined circumplex models of interest structure across time (Grades 8, 10, and 12), gender, and analytic method in a secondary analysis of vocational interest type (Realistic, Investigative, Artistic, Social, Enterprising, and Conventional) data generated from the American College Testing database (national sample of 69,987 students). Random samples of 1,000 participants were drawn representing males and females over the 3 time periods. The authors used structural equation modeling (SEM), the randomization test of hypothesized order relations, constrained multidimensional scaling, and circular unidimensional scaling. Results indicated differences in conclusions according to the method used. SEM analyses were not supportive of the circumplex structure, whereas the other methods were. Implications for research and practice are discussed.