Which has smaller class sizes: UIUC or Wellesley College?

The main tradeoff is scale: UIUC offers the resources and course breadth of a very large research university, but many introductory courses, especially in high-enrollment fields, can be taught in large lectures. Wellesley is a small liberal arts college built around discussion-based classes and close faculty interaction. As a result, Wellesley students are much more likely to have small classes from their first year onward.

At Wellesley, seminars and classes small enough for regular participation are central to the academic model. Professors typically teach undergraduates directly, office-hour access can feel more personal, and it is easier to become known as an individual in class. Some courses will still be larger, particularly popular introductory offerings, but large lecture halls are not the norm.

At UIUC, class size varies substantially by major and course level. Introductory classes in areas such as computer science, engineering, business, psychology, economics, and biology may enroll hundreds of students, often with discussion or lab sections led by teaching assistants. Upper-level and specialized courses can become quite small, and faculty relationships are absolutely possible, but students often need to seek them out through office hours, research, smaller electives, and departmental programs.

For the specific priority of consistently smaller, more participatory classes and easier day-to-day access to professors, Wellesley is the clear choice.