If you really want to know the class sizes, do not rely on CDS numbers. Instead, go to the college’s web site and see if the online class schedule lists class sizes, particularly those in your subjects of interest. Some other things can also be inferred:
- Class format. If the class has a lecture led by a faculty member with discussions led by TAs, that can be noticed, compared to classes that only have a lecture.
- Instructors. You may be able to look up instructor names to see if they are regular faculty, adjunct faculty, or PhD students (TAs).
Having a TA in addition to a faculty member teaching the class is not necessarily bad. Two instructors may teach slightly differently so that there is a greater chance of one of their methods fitting better with how you learn.