10 August 2010

Speeding Dolphins

In a recent visit to the National Aquarium in Baltimore, we saw a dolphin show. I really enjoyed it 'cause dolphins are awesome, but there's one thing the announcer said that really bugged me: "Dolphins swim faster than they should be able to."

It's sort of like the old myth that according to the laws of aerodynamics, bumblebees can't fly. The basic concept here is that people have a complete understanding of laws of motion (flight, swimming, etc), and these doggone animals are violating our laws.

The truth is, the animals have it right and we've got it wrong. When our math indicates one thing and observation reveals something else, um, that means our math is wrong. Rather than saying things like "Bumblebees shouldn't be able to fly" or "dolphins shouldn't be able to swim that fast," we should go with something like "Our understanding of physics is wrong / incomplete / etc." But let's not blame the animals when their behavior doesn't comply with our "laws."

In the case of dolphins' speed, the discrepancy is known as Gray's Paradox, posed in 1936 by biologist James Gray. He basically thought dolphins couldn't be strong enough to overcome the force of drag as they swim through the water. He was wrong, but that wasn't proven until 2008.

So, when there's a mismatch between our model and reality, don't criticize reality. Fix the model. When a theory is "mathematically correct but operationally wrong," it's wrong and needs to be modified... no matter how rigorous the math appears to be.

And yeah, this has something to do with project leadership. It's all well and good to have theories and guesses about how much a project should cost, how long it should take or how people should behave in certain situations. But when reality diverges from expectations, it's time to adjust the expectations.

5 comments:

Glen B. Alleman said...

It wasn't the theory that was wrong. Gray had the wrong number for the force. Theory of fluid dynamics was sufficient to explain the behavior IF he had the right number for the force.

In the estimating world this is called "anchoring" and "adjustment." Gray could not imagine that the dolphin could generate the force needed to swim at that observed speed - the "anchor." Then he could not reconcile tat since he was wathcing tem swim at that speed there must be some "magic" - a violation of physics - the "adjustment."

Search for Kahneman and Tversky for the basis of this understanding. They wrote their first paper in the late 70's the "anchoring and adjustment" process is in effect everywhere in project management, medicine, and especially finance.

Once you get through their papers, you'll never see the world the same again when it comes to numbers, opinions about numbers or advice about all things analytical.

This is a core problem in the defense acquisition world, that has yet to be addressed. The very essence of the estimating process is colored by the "anchoring and adjustment" that is built into our brains.

Glen B. Alleman said...

Dan, One more thought. Gray could have had a breakthrough if it weren't for is anchoring.

He could have deduced the force the dolphin generates by measuring its speed, knowing the body mass and measuring the fluid flow resistance across the skin.

But "anchoring and adjusting" preventing this knowledge from emerging.

That's the advise for all of us tasked with decision making in the presence of vague information.

Awadhesh said...

I couldn't agree more with you on that..

Seems those guys still don't know what they don't know :)

Bob W. said...

I guess we just need to be more like the Navy!

Anchors away.....

Stan said...

When realve does not fit our map of reality, better stick to reality...