The minimum number of students in a subgroup (e.g. Black students, English learners) that must be present in a school to trigger specific reporting and accountability requirements under federal law. An n-size is necessary to ensure data are not reported on so few students as to make identifiable personal information (e.g. reporting that all Latino students are advanced in math when there is only one Latino student means knowing the proficiency of a specific student, which is a violation of that child’s privacy). See also: subgroup