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 analyzes reviews to verify trustworthiness.
Though this was a text required for a class I have to say it's a great one. Informative and interesting. My favorite part is that the chapters aren't too long so I didn't feel bogged down with a ton of reading for class.