Without actually reading the book this statement pops out. If they only interviewed people for who the 10k hour rule worked and did not take a random sample of people then the book is completly biased and not scientific at all. Very well spotted. :thumbup: Have you had any formal training in statistics/science by any chance? I suppose you could read the book, and I was just giving an example. It also talks about things related to their successes, such as amazing luck. However, they couldn't have been successful without ten thousand hours in one particular field. Let me try and get this straight... So this 10,000 hour rule suggests that to master a particular field of expertise, you need to practice it for 10,000 hours? Do you mean that you need to practice for at least 10,000 hours or that all of a sudden you become a pro when you've racked up that magical figure? I know which one sounds plausible, and it's certainly not the latter. As people have said, we all learn at different rates, so the notion that all of a sudden you're a pro at something when you notch up 10,000 hours of practice is almost certainly not true. If you're suggesting that there was research proving this, provide the research so we can check it out for ourselves and pick out potential flaws. If you can't provide the research, then I'll remain skeptical.