经济学家 Hal R. Varian，有个小散文叫：How to Build an Economic Model in Your Spare Time（via: Kzeng），对别的学科的人也会有启发吧。摘录几段：

The first step is to get an idea. This is not all that hard to do. The tricky part is to get a good idea. The way you do this is to come up with lots and lots of ideas and throw out all the ones that aren’t good.

But where to get ideas, that’s the question. Most graduate students are convinced that the way you get ideas is to read journal articles. But in my experience journals really aren’t a very good source of original ideas. You can get lots of things from journal articles—technique, insight, even truth. But most of the time you will only get someone else’s ideas. True, they may leave a few loose ends lying around that you can pick up on, but the reason they are loose is probably that the author thought about them a while and couldn’t figure out what to do with them or decided they were too tedious to bother with—which means that it is likely that you will find yourself in the same situation.

My suggestion is rather different: I think that you should look for your ideas outside the academic journals—in newspapers, in magazines, in conversations, and in TV and radio programs…