75 vs. 150

As previously mentioned, a significant component of my new job at UBC this year is curriculum design for a first year cohort that will be taking, among other things, Physics, Calculus and Chemistry, and will have English language instruction somehow embedded into the courses or the support pieces around the courses. These students are mostly prospective Math, Physics and Chemistry majors. An interesting discussion we are having right now relates to class size; specifically class sizes of 75 versus 150.

To me, there are two main possible models for the physics courses in this program:

  1. Run them similar to our other lecture-hall first-year courses, where clickers and worksheets make up a decent portion of the time spent in class. In this case, 75 vs. 150 is mostly the difference in how personal the experience is for the students. Based on my own experience, I feel like 75 students is the maximum number where an instructor putting in the effort will be able to learn all the faces and names. With TAs embedded in the lecture, the personal attention they get in the lecture could be similar when comparing the two sizes, but there is still the difference of the prof specifically knowing who you are.
  2. Rethink the space completely and have a studio or SCALE-UP style of classroom, where students sit around tables in larger groups (9 is common) and can subdivide into smaller groups when the task require it. This would mean that 75 is the only practical choice of the two sizes. This type of setup facilitates transitioning back and forth between “lecture” and lab, but it is not uncommon for “lecture” and lab to have their own scheduled time as is the case in most introductory physics classrooms.

Going with 75 students is going to require additional resources or for program resources to be re-allocated, so the benefits of the smaller size need to clearly outweigh this additional resource cost. My knee-jerk reaction was that 75 is clearly better because smaller class sizes are better (this seems to be the mantra at smaller institutions), but I got over that quickly and am trying to determine specifically what additional benefits can be offered to the students if the class size is 75 instead of 150. But I am also trying to figure out what additional benefits could we bring to the student if we took the resources that would be needed to support class sizes of 75 and moved them somewhere else within the cohort.

What do you think about trying to argue between these two numbers? Have you taught similar sizes and can offer your perspective? I realize that there are so many possible factors, but I would like to hear which things might be important from your perspective.