A study traced changes in preferred occupation over a period of 5 years, from Year 9 (approximately age 14) to the first year beyond high school, for over 3,000 Australian students in a sample of 22 government schools. Reasons for changes in preference were probed in questionnaires administered annually. Interviews of a subsample of students and their parents were conducted during Year 10. Questionnaires were completed by a larger sample of about 600 parents. Analyses of reasons given for changed preferences showed that most commonly the reasons were changes in interests and experiences during work placements or "career" lessons. The important "barriers" in Gottfredson's scheme (1981), gender and social status, were rated among the 5 lowest in importance from the list of 15 reasons supplied. Perceptions of their own abilities were, however, ranked among the top five reasons by the students and had the strongest influence on projected compromises during Year 12. With increasing age, respondents were increasingly more likely to compromise by choosing a related course or job at a lower status level than to change field. Males were much more likely to compromise within gender-stereotyped boundaries than females. Sources of questionnaire items and items used to probe reasons for changes in preferred occupations are appended. (Contains 17 references and 8 data tables.) (YLB)