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.
It only mentions a broad overview of why child psychology is needed..... Piaget and Vygotsky theories are only superficially mentioned and not in any detail.... So if you are just beginning and want to know what uses child psychology has, you might go for it else skip it, there are better books around..