To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
I bought this book to help with the knowledge base within my department, and this books have certainly met all of the criteria! Couldn't be any happier with the information and content within these Books - Highly recommend :)