cata comments on Rationality quotes: October 2010

[cata]

One of my mentors once gave me a list of obvious things to check when stuff doesn’t work. Funny, years later I still need this list:

1. It worked. No one touched it but you. It doesn’t work. It’s probably something you did.

2. It worked. You made one change. It doesn’t work. It’s probably the change you made.

3. It worked. You promoted it. It doesn’t work. Your testing environment probably isn’t the same as your production environment.

4. It worked for these 10 cases. It didn’t work for the 11th case. It was probably never right in the first place.

5. It worked perfectly for 10 years. Today it didn’t work. Something probably changed.

edw519, Hacker News, on debugging.

I always need that list, too.

[sketerpot]

It worked for these 10 cases. It didn’t work for the 11th case. It was probably never right in the first place.

That one is counterintuitive, but true surprisingly often. Maybe not most of the time, but more often than you might think. And it picks the worst times to be right, let me tell you. Especially if it reveals a mistake in the math underlying everything you’ve been doing....

The solution, I suppose, is to learn to enjoy rewriting.