Coding epistemology

Jeff Atwood has a nice post about knowledge -- specifically, one way to learn something well.

I consider there to be the three levels of knowledge. They reflect my belief that knowledge needs to be shared to get the most value out of it.

1. knowledge you know. You read something, someone tells you, or you do it yourself, to the point where now you know it. But how do you know you know it?

2. knowledge you can explain to someone else. This requires you to organize the information. Many times, in the actual moment of explaining, you will suddenly realize a gap in your knowledge or a fallacy in your logic. I think this is akin to getting a call from your mom that she's coming over, and realizing only at that moment that your apartment is a mess; you're viewing yourself through someone else's eyes. And yes, the act has to involve explaining and a someone else, not just a mental exercise where you convince yourself that it could be done.

3. knowledge you can answer questions with. People react to your explanations in unpredictable ways; weird questions pop out. They try to apply it to things you'd never think of on your own, just as end users do things with your application that you'd never considered. These questions test the robustness and flexibility of your knowledge -- or, said another way, they test whether your understanding is at the implementation or the abstraction level.

You are more likely to succeed at numbers 2 and 3 if, as in Jeff's example, you wrote something yourself from scratch, as opposed to someone just explaining it to you once. Someone explains something to us, we can walk away with a false sense of security in our knowledge, which easily crumbles in the face of simple questions.

Implicit in number 3 is the possibility that someone's question may blow up your knowledge, perhaps due to false or missing assumptions.

For these reasons, I like to have a "training" on any major new functionality, either as a group, or one-to-one. To verify that the trainee (which could be me) is truly walking away with knowledge, that person will later have to explain it to the next person. And take questions.