As a lecturer, you probably teach in both large group and small group contexts. For some academics a large class might be 40 students, for others it might be 400. The definition of "large" and "small" classes can be quite variable depending on: the discipline, the nature of the class (e.g. lecture or lab work), the level of the course (e.g. undergraduate or postgraduate) and the perceptions of lecturers and students.