Should we worry that uni student numbers have grown more quickly than academic staff numbers? The history of school research on student:staff ratios suggest that we should be cautious about making lower SSRs a policy priority. Most analysis has found little or no educational benefit in reducing school student:staff ratios. Increased SSRs may be a sign of higher productivity rather than a problem.
Given that uni students are supposed to be more independent learners than schools students, universities (with rare exceptions like the Oxbridge tutorial system) have always used large groups methods of instruction such as lectures. Unis can teach many more people at the same time than schools.
On interesting question is whether if the class expands beyond the size where personal interaction is feasible, does it matter whether there are 100, 200, 300 or more students in the room? If, as the school research suggests, it is teacher quality that matters most to learning it might be better to have the best lecturer teach a class of 300 than to have six not-so-good lecturers take six classes of 50.
On the other hand, bigger classes may mean more scope for disruption or distraction of students by misbehaving students, and complications from teaching students with a wide range of abilities if opportunities to stream are lost (in my own limited lecturing experience 20 years ago teaching first-year politics, range of abilities was one of the biggest problems as I had some students who were quite well-informed and others whose knowledge of politics was close to zero).
In tutorials, I can see much stronger theoretical reasons for believing that bigger is not better than for lectures. This is a chance for students to ask questions, and for the tutor to monitor the students. If there are too many in the class, students may be too shy to ask questions, be too easily dominated by loud students, or simply shirk. And it is harder for tutors to keep track of all the students.
Though SSRs don’t seem to be much used in analysis of university performance, I have found some papers on class sizes.
In research based on an unamed UK university the analysis used numbers of students enrolled to take the final exam; a perhaps less than ideal measure given that it is consistent with a wide variety of actual classroom practices. It found that large classes were associated with lower marks, though not in the 30-100 class size range (counter-intuitive, as I would have thought that this is precisely the range in which it becames hard for the lecturer to know and attend to everyone).
A study of an Italian university with regulated class sizes found that class size (as in people in the room) had a largish effect on pass rates. ‘An increase of 50 students in class size reduces the student’s probability of passing an exam by about 8.7 percentage points.’ They were comparing students with the same teachers, so that was not a confounding factor.
The most interesting study I have seen to date, also on an Italian university, was able to measure both academic results and subsequent salaries. The academic effects were statistically significant but of modest apparent importance. An increase of class size by 20 from the mean of 131 resulted in a mean reduction in grades by about 1/3 of a grade point. But an increase of class size by 20 was associated with a lower monthly starting salary of about 80 Euros, or 6%. It’s not obvious to me why such a small difference in grades could translate into a non-trivial difference in salaries. But if this finding could be replicated, it could provide a financial justification for reducing class sizes.
I’d want to see more research in this area, but unlike the schools research the persistent pattern of findings is that class sizes do matter.