How ratings and rankings work

Every score on College Actually comes from student reviews. Here's exactly how they're combined, so you can judge how much to trust a number.

One person, one review

Each account gets one review per place. Posting again edits it rather than adding a second. Reviews are rate-limited, and an account must confirm its email before it can post.

Verified students count more

Students who verified with a school email get the Verified Student badge, and their ratings count fully. Ratings from unverified accounts count half. This keeps scores grounded in people who were actually there, and makes it much harder to flood a page with throwaway accounts.

Averages you see on a page

The stars on a page are the weighted average of its reviews, using the weights above. Category scores (Noise, Value, Food…) are averaged the same way, from the reviewers who rated that category.

Some categories describe rather than judge. For Difficulty and Workload, a 5 means “very hard” or “heavy”, not “best”, so they're never used to rank anything as best, and a hard or heavy course doesn't get a lower overall rating for it. “Would take again” on a course and “would live here again” on a residence hall only show a percentage once at least 3 students have answered, counting only those who did.

Rankings reward a track record

A plain average would let one 5-star review beat two hundred 4.6-star reviews. Rankings use a Bayesian average instead. Every place starts as if it already had a set number of “typical” reviews (usually 10), where typical is the average for that kind of place at this school. Real reviews then pull the score up or down:

ranking score = (10 × typical score + sum of weighted ratings) ÷ (10 + total review weight)

• With few reviews, a place stays close to the typical score, however good or bad those reviews are.
• With many reviews, the typical score barely matters and the real average shows through.
• A place also needs a minimum number of reviews (usually 3) to be ranked at all. Below that it's listed under “Not enough reviews yet”.

Tag-based rankings

Lists like Best Late-Night Food or Best Date Spots include places that are categorized that way, or that at least two reviewers have tagged that way. Within the list, places are ranked by the score above.

Professor rankings

Professors are ranked more cautiously, because they're real people. A professor needs at least 5 reviews to appear, and a list is only shown once 3 professors qualify. “Highest rated” uses the score above; “Most would take again” is pulled toward the average answer the same way, so 5 out of 5 doesn't beat 95 out of 100. Difficulty never counts: a hard class can be an excellent one. “Would take again” on a professor's page only appears once at least 3 students have answered.

Culture survey results

The student culture survey (competitive or collaborative, how easy it is to make friends, the dating scene) is answered anonymously by verified students. We show only the average answer and how many people answered, never individual answers. Any group smaller than five is hidden, and when you filter by class year, a year is also hidden if everyone outside it would be fewer than five, so no small group can be worked out by subtraction.

What doesn't count

• Reviews waiting for a moderator, or hidden or removed by one.
• Reviews hidden automatically after three separate reports, until a moderator decides. A few reports can pause a review, but only a moderator can remove it.
• Sample reviews marked Demo once the site switches off demo content.

What we never do

• Accept payment to change a score or ranking.
• Rank or rate individual people.
• Label a place “unsafe” or “to avoid” based on anonymous posts.