So... I don't own a startup, have never done user interface testing and am generally unqualified to talk about how to design these things. However, I'm not bad

So... I don't own a startup, have never done user interface testing and am generally unqualified to talk about how to design these things. However, I'm not bad at statistics and logic, and I'm sorry, but the logic here is pretty bad. The author is comparing a user (edit: really user behavior on a feature/icon that no one gets) to a fair coin. The conclusion he comes to...? They are not the same! Not exactly a lot of insight. A much more fair comparison, in the example given, is comparing the user to a heavily biased coin. In this case, a coin that (almost) always comes up heads. With this coin, the convergence is much faster. The (almost) fair coin is a better comparison to a feature that (almost) half of your users do/don't get. So, if you try with 30 users, 14 like something and 16 don't, you need more data! But, if you try with 30 users, and 29 like it and 1 doesn't, you can stopy.