[quindecagon]

Re point 1:

> This was the early 1970s, he said, why were these engineers so confident in their calculations? As guessed by many in the audience, the reason for that was "computers". In fact, when they won the bid, they told the city of Hartford that they could save half a million dollars in construction costs "if you buy us this new, whiz-bang thing called a computer". It turned out that the computer worked fine, but it was given the wrong inputs. There was an emotional investment that the engineers had made in the new technology, so it was inconceivable to them that it could be giving them the wrong answers.

[kerkeslager]

Yes but we don't ever find out why they got the inputs wrong.

Does this sound like expertise to you?

[mjw1007]

I think "wrong inputs" here is an odd way of saying that the model was bad (presumably to distinguish that problem from outright bugs in the design software or computer hardware failure).

https://eng-resources.uncc.edu/failurecasestudies/building-f...

says

« The roof design was extremely susceptible to buckling which was a mode of failure not considered by in that particular computer analysis and, therefore, left undiscovered. »

[kerkeslager]

Okay but again: was this failure because their expertise misled them?

[mjw1007]

Not as far as I can see, no.

That article contains the following claim: « Computers, however, are only as good as their programmer and tend to offer engineers a false sense of security. »

which matches the "dark side of expertise" talk's bit about « There was an emotional investment that the engineers had made in the new technology, so it was inconceivable to them that it could be giving them the wrong answers. »

That seems to me to be a different issue to being misled by one's own expertise, and in any case neither source bothers to give any evidence that it's true (that is, that the computer's involvement was the cause for the unreasonable trust in the model's results).

[bryanrasmussen]

No. In fact if they were misled by computers and they were not software engineers, which I had assumed they were not from them being called "Design Engineers" in the anecdote, it follows that they were not misled by their expertise but their assumptions of expertise from this unknown mysterious powerful new thing that a lot of money had been poured into.

[phkahler]

They ignored the actual fact that it was sagging more than predicted and insisted the calculations were right. That might be ok, but someone allowed the project to proceed without explaining the contradiction. Real observations were dismissed in favor of believing in the expertise.

[kerkeslager]

Hm. You're saying that inexpert decision-makers were misled by experts?

That is true, but I'd argue that the article is making a different claim: the article is claiming that experts are misled by their own expertise.

[akamoonknight]

It seems like one difficulty is in knowing what expertise is important? Assumedly the contractors thought they had expertise, but were lacking. The firefighters assumedly thought they had expertise, but we're lacking. What expertise do I think I have, but am actually lacking?

[kerkeslager]

Yeah, that's difficult. The only answer I've found is experience. Gaining experience for yourself is painful because it's slow, and part of the experience is consequences of your mistakes: in fields like fire-fighting (or rock climbing, which I love) your mistakes can literally kill you. So hopefully you learn form other people's experience and mistakes as much as possible.

[mcguire]

The experts were led to disregard reports of sagging by their trust in the computer model.

[spaced-out]

>They ignored the actual fact that it was sagging more than predicted and insisted the calculations were right.

Seems like they lack the expertise needed to properly evaluate their model.

[geggam]

or experience can create a bias where you know you are right even when the evidence says otherwise.

Age usually humbles people by them experiencing this often enough they tend to check things... if they mature properly