The evidence is clear. Students need to attend school on a regular basis to succeed. If the purpose of school is to help students learn and development, then being there is important.
Until quite recently, however, we did not regularly measure the extent to which the students enrolled in a school were attending on a regular basis. Until 2017 or so, the most common measure used to measure a school’s attendance was average daily attendance (ADA), or how of the many students enrolled in the school are present on the typical day. It turns out that this measure hides as much as it reveals. This is because it’s very possible for a school to have an ADA in the low 90’s, but still have 20% of its students chronically absent -- missing ten percent (or about a month) or more of the school year.
Since the mid 2000’s, Hedy Chang and her organization, Attendance Works, has called attention to chronic absenteeism, its consequences and prevalence, and optimal solutions.