How does undergraduate teaching quality compare between Carnegie Mellon and Princeton?

The main tradeoff is that Princeton offers a more consistently undergraduate-centered classroom structure across fields, while Carnegie Mellon can provide exceptionally effective, practical instruction in technical subjects but with a more variable experience by department and course.

At Carnegie Mellon, teaching is often strongest when students want demanding, applied learning: problem sets, studios, labs, critiques, and team projects are central in areas such as computer science, engineering, design, drama, and business. Many instructors are outstanding at breaking down technical material and maintaining well-organized courses. However, some foundational courses can feel fast-paced and highly structured, and the level of professor contact may depend more on the specific program, class size, and whether a course is taught by tenure-track faculty, teaching faculty, or graduate instructors.

For your stated priorities, Princeton has the edge in undergraduate teaching overall. It is more likely to give you consistently small, discussion-based classes and regular faculty interaction beyond the lecture hall. Carnegie Mellon is the more compelling choice only if you particularly value intensive, hands-on technical instruction and are comfortable being proactive about office hours and building relationships within a rigorous, project-heavy environment.