Using student achievement data from British Columbia, Canada, this study is an exploration of the differences that lie within the private school sector using hierarchical linear modeling to analyze the data. The analysis showed that when controlling for language, parents' level of educational attainment, and prior achievement, the private school subsectors had small but important differences in average performance compared to one another and to public schools. The study suggests that mission might matter more in parental school choice decisions than academic achievement and implications of this for school choice are explored. (Contains 3 tables and 2 figures)