This paper illustrates the use of exploratory focus groups to inform the development of a survey instrument in a sequential phase mixed-methods study investigating differences in secondary students' career choice capability. Five focus groups were conducted with 23 Year 10 students in the state of New South Wales, Australia. Analysis of the focus group data helped inform the design of the instrument for the second phase of the research project: a large-scale cross-sectional survey. In this paper, we discuss the benefits of using focus groups as an initial exploratory phase in a sequential phase mixed-method design and demonstrate how the findings from this initial exploratory phase informed the development of the survey questionnaire to be used in the main phase of the research. The paper will be of interest to researchers considering the use of exploratory qualitative methods to enhance the quantitative phase in a mixed-methods study.