Amazon calculates a product’s star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers, and factors that establish reviewer trustworthiness.
I read this in French and English, Why Men Marry Bitches, and I believe that Sherry Argov's books should be required reading for every woman. It's the only book that discusses a woman's dignity, and the complex issues in a relationship. Highly recommend!