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 am a huge fan of Camilla d'Errico and have the previous adult colouring book of hers. Again this is truly a fantastic book and i've already been having fun with it. The drawings are beautiful and well designed, couldn't be happier!