Where there are large differences in a population it is often useful to compare sub-groups in terms of factors which are known to influence the key variable under investigation. The key variable in this study was the decision to stay on or leave school at the senior secondary school level. In a longitudinal study of 494 students, Hemmings (1994) identified and demonstrated that 13 factors influence the decision to stay or leave. The standard scores on each of the measures of the 13 factors were compared for those who stayed and those who left. Complementary information was obtained through a series of case studies with a sub-sample (N=25). This procedure of comparing statistically the differences between sub-groups, and then exploring these differences in terms of a case-study analysis, proved to be fruitful and meaningful. In using this procedure the combination of statistical and case-study analyses avoided the pitfalls of relying solely on one method. This approach is commended to other researchers.