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 is NOT what I was expecting! It's nothing more than mathematical equations and references to the main book. I thought it might have some useful conversion tables or SOMETHING useful for a home machinist! What a waste. I can't find one single thing in this book that would be useful to me. Will be selling my copy as quickly as possible if anyone will buy it! (wish I didn't!!!)