Changes in student-affective entry characteristics were examined in an educational−vocational intervention at Finnish comprehensive school. The conceptual framework constructed from attitudes as learned dispositions (Fishbein & Ajzen, 1975) and self-determination (Deci & Ryan, 1985) was tested in a longitudinal study. A person-based survey questionnaire was designed, piloted, and validated. Spearman−Brown reliability was calculated. In the first observation, 669 (Time One Cohort), and in the second, 649 (Time Two Cohort) subjects (girls and boys) of mean ages of 14.5 and 16.0 years took the Web-based survey. The tested hypotheses were (a) variables of self-determination, self-regulation, and intrinsic and extrinsic motivation would emerge as attitudinal domains in work−life orientation; (b) the experiences during the implementation of a work−life orientation program would decrease the effects of seventh-grade student background factors at the end of the program in the ninth grade, and (c) work−life orientation would be effective and have efficacy in changing student attitudes in relation to further education and occupations. Three factors emerged in the Maximum Likelihood Factor Analysis. The factors Independence, Self-Direction, and Flexibility were used as the dependents in repeated measures in a general linear model. The factor means were subjected to a paired samples t test. There was development toward stronger Independence and Flexibility in the case of both genders. The boys had gained the girls’ seventh-grade lead at the end of the program. Self-Direction did not show any changes. Empirical findings tentatively supported the program’s efficacy in changing entry characteristics.