The situation that calls for testing feels like being confused or curious.
The thought that generates a test looks like this: "If X is true, it is (more/less) likely that Y is true. I can examine Y by doing ___."
For example, one day my computer was running slowly. There were a bunch of possible explanations, but my room was hot, dusty, and it'd been a long time since I cleaned it out, so I suspected the slowness was because of overheating. "If my computer is slow because of overheating, it is less likely that it will be slow if I remove the case to increase ventilation. I can examine that by removing the case." I pull the case off, and the computer runs normally again.
Most of the examples tend to be banal, though, and so I've forgotten them. (Not quite sure how I remembered that one.)
Ideally you should also point a room fan at the inside of the computer after you take off a panel. Some systems, especially small form factor PCs and rack mount servers, actually need the case in order to be properly cooled. Removing a panel means that e.g. an exhaust fan no longer forces air across passively cooled components near the intake.
I've read a bunch of times on LessWrong about how important is to test things. It makes sure your beliefs are paying rent and helps you verify your hypotheses. Testing ideas is obviously important to science, and it's about as obvious that testing ideas in everyday life can serve the same purpose. I know all this, and I want to be the type of person that goes out and verifies my beliefs by experiment, but still I can't think of a single time I've done it. I don't think I even recall thinking, about some everyday type of thing, "hmm how could test that?" (apart from trivial trial-error computer related things). Anyway, I was wondering if some of the you could give me some examples of times you've done this. I'm thinking maybe I'll be able to pattern-match the kind of things you guys have done and hopefully recognize in the moment when I'm looking at a testable thought.
Thanks.