> the over-time aspect is kind of self-evident It's self-evident that, in order to become a master at anything, you have to pass through increasing levels of c

> the over-time aspect is kind of self-evident It's self-evident that, in order to become a master at anything, you have to pass through increasing levels of competence to get there. It is not at all self-evident, at least not to me, that while a particular person is going through that process, their estimate of their skill vs. their actual competence will be similar to what Dunning and Kruger found when they compared different people's confidence vs. competence at a single time. > just because the data collection wasn't done over time doesn't mean that the principle behind the effect isn't time/effort based. It could be, but a study that only collects data at one point in time can't possibly provide evidence either for or against any such hypothesis. > competence can only increase over time This is simply false. Skills and knowledge that aren't used can deteriorate. People can forget things they used to know. In a much narrower sense, we would hope that if a person is studying a subject with the intent of mastering it, that their competence will only increase over time. But even that's not always true. > there is lots of research on how mastery is gained. I don't have time to throw a bunch of it at you, but I suspect you won't need me to in order to see my point. Sorry, but since, as you can see from the above, I don't agree with several of your key points, you're going to have to back them up with research if you want me to consider them further. If you don't have time for that (which is fine--we're all posting here in our spare time), then we'll just have to disagree.