An approach used in psychology tests for questions people are embarrassed to answer: add a random number to each rating. The aggregate effect is the same (if a

An approach used in psychology tests for questions people are embarrassed to answer: add a random number to each rating. The aggregate effect is the same (if a random number from 1-5 is added to each reviewer's review, on average, you just need to subtract 3 from the average review score), but reviewers may feel more-free to be honest. More reviews are required to get an accurate review, but the reviews may be more accurate. The larger the random spread is compared to the rating's dynamic range, the greater the obfuscation, and the more reviews you need to learn something new.