eligibility, disability status, and English language learner status, and to track their progress over time. These subgroup statistics are often not comparable across schools, districts, or states due to differing methods and rates of identification and reclassification into and out of the subgroup. Furthermore, the methods by which students are placed into subgroups can lead to inaccurate judgments about educational efficacy in a school system for members of the subgroup. For English language learners, inaccuracies are introduced because classification into the subgroup changes over time, and the rate of reclassification is correlated with dropping out. For students with disabilities, underidentification of disabilities and different methods of classifying disabilities result in lack of comparability. Furthermore, because some students with disabilities are expected to remain in school for more than four years, the subgroup statistics for students with disabilities will disproportionately be affected by decisions about the number of years allowed for graduation in the indicators (e.g., four-year versus five-year rates).

The main purpose of subgroup statistics is to gauge the degree to which schools, districts, and states are serving particular groups of students. To make these judgments fairly, alternative statistics should provide supplemental information for subgroups. With regard to graduation rates for these subgroups, we recommend: