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.
The book is boring and the information is basic. I believe that we can learn something from any book,, it's the percentage of useful information that we learn that separates a good book from a great book... I wasn't able to take much insight from this book