"Haskell discounts the very useful choice of reasoning about your code after it runs, favoring, instead, all-upfront reasoning, often at the expense of facilita

"Haskell discounts the very useful choice of reasoning about your code after it runs, favoring, instead, all-upfront reasoning, often at the expense of facilitating the former. There are some domains where figuring everything up front is very important. Others, where trial and error is far more productive." Yes people seem to learn much better by example. The worst teachers (we have all had them) are those who jump straight into the abstraction that solves the problem instead of going through some examples first. If they cover a few specific examples with specific solutions then the student will almost invent the abstraction themselves. The same thing came up recently about pitching startups. If you don't describe the problem first with specific examples then people won't even recognise the solution (and often these people are far from stupid). In general for most people if they are trying to do something innovative they are rarely definitive about it at first. If you asked them to explain it or prove it they couldn't. They start with a hunch, do something ill defined, and then refine it as they go. Even mathematics is like this, except that often once someone has discovered and understood something, they explain it as if they were definitive about it all along - which can be misleading to say the least.