In an evaluation of the Self-Directed Search (SDS), a self-administered vocational counseling experience based on Holland's theory of vocational choice and his occupational classification, a total of 1,092 students in 10th, 11th, and 12th grades in four high schools were divided into three treatment groups. One group took the regular, published version of the SDS, while the second group took a version of the SDS which did not contain the "self-directed" aspects. The third group served as a control, receiving no treatment. Evaluative criteria were selected that would assess the special effects of the SDS as well as effects commonly expected from more typical vocational counseling procedures. Results revealed that both versions of the SDS were effective in increasing the number of occupations being considered, but students taking the published version were considering more appropriate occupations based on their activities, competencies, interests, and self-ratings than those who took the non-self-directed version. In addition both versions of the SDS were effective in increasing satisfaction and certainty about vocational plans, and the effectiveness of both versions was evaluated as moderately positive by the students. Sample student interest questionnaire, opinion form, and vocational guidance questionnaires are appended. (Author/SB)