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.
Simple story about a wombat's life written in a diary format from the wombat's point of view. Wombats are stubborn beasties with minds of their own and this book perfectly captures the nature of a wombat which will do its own thing regardless of consequences. And it's beautifully illustrated by Bruce Whatley. Superb.