RateMyProfessors.com uses a 1 (low) to 5 (high) scale to evaluate professors' helpfulness, clarity, easiness, textbook use and student level of interest before taking the class. "Hot" awards one chili pepper, and "not" subtracts a chili pepper. Student optionally include their class grade averages and written comments.
Overall quality, shown with the smiley face, averages helpfulness and clarity. Easiness, student interest and grade averages are informational only. Overall hotness is a calculation of plus for "hot" and minus for "not." Students also rate schools and campuses based on facilities, job placement, location and general reputation.
Concerns over ratings on the site cite the problem of self-selection. Students with very good or very bad experiences are motivated to provide reviews. Another problem is that the site does not verify that a student ever took a class with a professor or even that the reviewer is a student. Although malicious comments are against the terms of service, malicious reviews exist. The chili pepper rating is controversial, as even a positive rating on appearance can create an uncomfortable classroom.