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 needed a basic book to teach my eleven-year old how to play guitar. I was pretty wary when I saw the cover and thought it might be too easy, but I was pleasantly surprised to find it was written in a clear way that wasn't childish.