8.9 Class Size

The size of the class matters for many reasons. From an institutional perspective, this often comes down to $$$; how many can be taught at once and at what cost. It would be nice to think that quality is also considered, but in some cases it is mere lip service. Quality may indeed be considered in other cases, but what is considered good and acceptable quality by the people who fund and build the rooms, might be a different definition than that used by those who have to use the room and actually teach. See the note for more on classroom design. The physical facilities and institutional constraints are part of any discussion on class size.

Why worry about class size?

• The size can impact the choice of methods; what will or will not work. Are there enough students? Are there too many students?
• The number of students might be ok, but does the class size fit the classroom for the methods being considered? Some method require space and arrangements suitable for in-class exercises, think-pair-share activities, and so forth. While the number of students might fit the legal occupancy limits, the pedagogical limits?
• The class size will impact any bi-directional interaction with the class. Is there enough time in the lecture to have all of the worthy questions aired? If the class is too large, there will be a lack of time.
• If the class has think-pair-share and dialog as it's goal, the number of groups and how many groups can be heard per lecture, how many over the term, how many interactions per term will be defined by the class size. For example, take 100 as a number, 25 groups, in-class interaction discussion, say 5 per class (high estimate), and this means that if care is taken, it would take 5 lectures to interact with each. If the course has 20 lectures, that will give each group four touch points. And, five groups in a lecture to really do a decent interaction will take 15-25 minutes of lecture time. This might be warranted, but what happens if there are 100 groups? You do the math.
• If part of the teaching method is making eye-contact, making every student feel involved at least once per lecture, the number will matter.

• If you have to work the room for in-class activities, the number of assistants and tutors will also be impacted. Assume a ratio of 8-to-1 for 'tables' per helper. Do you have enough skilled helpers?
• The size of the class can compromise the desired number of assessments and types of assessments if inadequate resources exist; that is, the per student effort per activity can be compromised.
• The size of the class can also affect office hours for both instructor and assistants. It is easy to say that an extra TA or two will be assigned, but it is also a matter of qualified TAs, not 'just a TA'. While extra TAs can deal with many of the extra load, extra students imply, there is still only one instructor (in most cases).
• For courses that have a high cognitive complexity, we have found a number around 70-80 to be manageable. More is a problem. Less is a problem.
• If the course involves labs or physical activities, space and resources can also be a problem. If the labs are not the right size, or insufficient equipment is available, issues can arise.
• Sudden, unplanned increases in a class enrollment can create problems. There are times that the numbers will increase past the sweet-spot and many activities and methods will have to be reworked. Many methods and approaches are size dependent. Changing from on-campus to online, or from online to on-campus can imply an almost 100% different delivery and execution.

Further reading

• Monks, J. and R.M. Schmidt (2011). The Impact of Class Size on Outcomes in Higher Education The B.E. Journal of Economic Analysis & Policy Contributions, 11, 1, pp. 1-17.