There are some problems that don't have a correct answer [Harford]

From "Trial, error and the God complex", a TED talk by Tim Harford, 2011.

So I say, okay, fine. You think it's obvious? I will admit it's obvious when schools start teaching children that there are some problems that don't have a correct answer. Stop giving them lists of questions every single one of which has an answer. And there's an authority figure in the corner behind the teacher's desk who knows all the answers. And if you can't find the answers, you must be lazy or stupid. When schools stop doing that all the time, I will admit that, yes, it's obvious that trial and error is a good thing.

When a politician stands up campaigning for elected office and says, "I want to fix our health system. I want to fix our education system. I have no idea how to do it. I have half a dozen ideas. We're going to test them out. They'll probably all fail. Then we'll test some other ideas out. We'll find some that work. We'll build on those. We'll get rid of the ones that don't." When a politician campaigns on that platform, and more importantly, when voters like you and me are willing to vote for that kind of politician, then I will admit that it is obvious that trial and error works.