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.
This book shows the concept of psudocode that use to design computer program which independent of any computer programming language. But I prefer to write pseudocode in mathematical terms than using plain English which explain in this book, such as SET i to 0 : in the book, i = 0 : I prefer this. In my opinion, mathematical term more easy to understan in first glance than in plain English.