This is from book which I have been reading a lot. It is one of my favorite in area of testing. Now I finally have some explanation why I am studying all the time - I want to be a good tester. (Maybe I should rethink my current position as method expert and start looking for open vacancies for testers...)
Book is "Lessons Learned in Software Testing" by Cem Kaner, James Bach and Bret Pettichord.