This file shows average class sizes and size of smallest and largest class for each school, broken out by grade and program type (General Education, Self-Contained Special Education, Collaborative Team Teaching (CTT)) for grades K-9 (where grade 9 is not reported by subject area), and for grades 5-9 (where available) and 9-12, aggregated by program type (General Education, CTT, and Self-Contained Special Education) and core course (e.g. English 9, Math A, US History, etc.).

Official class size data for grades K-9 is based on October 31, 2008 Audited Registers; Core course class size data for MS CORE and grades 9-12 is based on January 23, 2009 active registers. Where ninth grade data is not reported by core course - For middle schools using MSPA (ATS) or HSST to program, average class size is reported by core course, as well as by official class.
- For high schools, sections with matching day, period, room and core subject, and combined enrollment less than 34 are assumed to be co-teaching situations. In the report, duplicated sections are subtracted as "MATCHED SECTIONS" and paired sections are added back as "ASSUMED TEAM TEACHING".