The ratio of students per teaching staff is the total number of full-time equivalent students enrolled at a specific level of education divided by the total number of full-time equivalent teachers at the same level. Teachers refer to professional personnel directly involved in teaching students: classroom teachers, special education teachers and other teachers who work with students as a whole class in a classroom, in small groups in a resource room, or in one-to-one teaching inside or outside a regular classroom. This does not include teachers’ aides and other paraprofessional personnel.