Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
Good for people who are interested in the psychology of environment. It reviews the extant literature well and contains a balance of scientific and artistic perspectives. It also manages a very balanced and self-aware voice. Neither carried away by the science nor cynical.