I have given only 1 star because the book does not give the answers to the many exercises and questions. The book is aimed at beginners. Is the beginner supposed to assume he got the answers right?
I agree with the other reviewers that Koop explains the statistical concepts in simple, easy-to-understand terms but I really don't think there is any excuse for omitting an appendix with the answers to questions.
This book was probably my best book purchase at University. It clearly explained concepts which I thought were too complicated for me to ever understand. It didn't go into too much detail which made the book an easy read. Not at any point did I feel overwhelmed.