I would have given this 4 if I had no idea about systems theory, but as an electronics engineer, many things explained in the book are daily stuff for me. So I unfortunately can not say I have learned too much reading this, which is not a bad thing at all. But it was a little boring at times. From an engineering perspective, the explanations for fundamental terms in systems theory are straight-forward and clear and author makes them understandable for the ones which are not exposed to these kind of thinking or problem solving daily. So leaving my background on the side, I can easily say it was a nice and easy read. One thing bothered me most of the time though, is that the author chooses to give an unnecessarily lot of examples on basic topics, especially in the beginning of the book. I would have left many of them out. I just skipped the parts where more than one example is given actually.