[yusefnapora]

Have you ever been in _any_ situation in which you've had complete data?

[antisthenes]

Absolutely, it happens all the time. I'm surprised to even hear this question on a nerdy computer platform.

https://en.wikipedia.org/wiki/Game_theory

Plenty of games with complete information. Here's a famous one.

https://en.wikipedia.org/wiki/Chess

[arp242]

Any real-world situation (outside of simple trivial matters)? War, health care, immigration, economics, running a business, those kind of things. Chess is just a game and not very important. No one is talking about games here.

Getting a good overview of what happens at scale is exceedingly hard, and on pretty much all of this you need to take in more inputs than what can be strictly quantified.

[itsoktocry]

So if you don't have "complete" data, you just start winging it? I never understand this argument.

You measure what you can, that moves you forward.

[LaundroMat]

No, that's exactly what the McNamara fallacy is about.

"US Air Force Brigadier General Edward Lansdale reportedly told McNamara, who was trying to develop a list of metrics to allow him to scientifically follow the progress of the war, that he was not considering the feelings of the common rural Vietnamese people. McNamara wrote it down on his list in pencil, then erased it and told Lansdale that he could not measure it, so it must not be important."

https://en.m.wikipedia.org/wiki/McNamara_fallacy

[rawgabbit]

The problem, for the US involvement in Vietnam, was that "body count" was irrelevant. The only metric that mattered was the willingness to fight of communist Vietnam, China, and the USSR. The problem is that "will" is not numerical. It is willingness to fight among the political elite of those countries and they include domestic factors, economic factors, and military factors. If anything, McNamara's fallacy is like comparing the iPhone and Android and saying the only thing that matters is screen size.