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Does Diversity Trump Ability? An Example of the Misuse of Mathematics [pdf]

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Re: Does Diversity Trump Ability? An Example of the Misuse of Mathematics [pdf]

#51

Post by roguecoder »

bayesianhorse wrote: post #9

In finance it has long been known that diversity in a portfolio can often trump the performance/ability in a particular stock. Turns out, you can see portfolio theory popping up outside of financial markets, not only in assembling a team, but also advertising campaigns, ant colonies and bacterial colonies. And yes, I know that the linked article debunks a paper that abuses math... It's just that portfolio theory is a…

Also the empirical studies from MIT about group problem solving. They have observed that diversity contributes more than the abilities of the individuals. It's not that the idea that diversity trumps ability in an unpredictable situation is wrong: it's that the original mathematical argument doesn't demonstrate that.

Re: Does Diversity Trump Ability? An Example of the Misuse of Mathematics [pdf]

#52

Post by spinlock »

bobthechef wrote: post #37
johnbender wrote: post #14

Earlier quoted context omitted.

It's important to realize that common sense is never a replacement for a proof or emperical result. That is, common sense is not sufficient to refute the claims made by the original paper. The power of science is that it often defies reasoning and in so doing provides new insights into how things work.

Are you being intentionally facetious? How could science defy "reasoning"? Is science some mystery cult that is shrouded in obscurantism and lack of intelligibility? Or poor choice of word perhaps? Science is most definitely about reasoning and reasoning properly. You must realize that proof and empirical result are never a replacement for common or good sense. The very attitude that proof is self-sustaining is as si…

> Are you being intentionally facetious? How could science defy "reasoning"?

Science often defies reasoning. Think about the history of our understanding of gravity. Newton was ridiculed when he proposed his model of gravity. And, Einstein was considered a quack for years until people understood what he was talking about.

Re: Does Diversity Trump Ability? An Example of the Misuse of Mathematics [pdf]

#54

Post by bayesianhorse »

Guthur wrote: post #17
bayesianhorse wrote: post #9

In finance it has long been known that diversity in a portfolio can often trump the performance/ability in a particular stock. Turns out, you can see portfolio theory popping up outside of financial markets, not only in assembling a team, but also advertising campaigns, ant colonies and bacterial colonies. And yes, I know that the linked article debunks a paper that abuses math... It's just that portfolio theory is a…

In my opinion the reason "portfolio theory" works in the cases that you mentioned is that it most perform well across a time series within a highly dynamic environment. But if one is allow to pick an optimal team for each discrete problem then it will surely outperform. In my mind diversity will help when you have little to no a priori knowledge and then for can not predict what attributes you will need.

Have you never seen a software development project which ran into unanticipated problems?

What about "knowledge work" is not a highly dynamic environment?

Re: Does Diversity Trump Ability? An Example of the Misuse of Mathematics [pdf]

#55

Post by bayesianhorse »

ohsnap wrote: post #18
bayesianhorse wrote: post #9

In finance it has long been known that diversity in a portfolio can often trump the performance/ability in a particular stock. Turns out, you can see portfolio theory popping up outside of financial markets, not only in assembling a team, but also advertising campaigns, ant colonies and bacterial colonies. And yes, I know that the linked article debunks a paper that abuses math... It's just that portfolio theory is a…

Portfolio theory does not work here. Totally different concepts. MPT is about minimizing risk - not trumping the performance of a stock.

MPT is not about "minimizing the risk". It's about minimizing risk for a desired reward. In an abstract way of speaking, selecting team members is very similar.

Re: Does Diversity Trump Ability? An Example of the Misuse of Mathematics [pdf]

#56

Post by SnacksOnAPlane »

spinlock wrote: post #52
bobthechef wrote: post #37

Earlier quoted context omitted.

Are you being intentionally facetious? How could science defy "reasoning"? Is science some mystery cult that is shrouded in obscurantism and lack of intelligibility? Or poor choice of word perhaps? Science is most definitely about reasoning and reasoning properly. You must realize that proof and empirical result are never a replacement for common or good sense. The very attitude that proof is self-sustaining is as si…

> Are you being intentionally facetious? How could science defy "reasoning"? Science often defies reasoning. Think about the history of our understanding of gravity. Newton was ridiculed when he proposed his model of gravity. And, Einstein was considered a quack for years until people understood what he was talking about.

There's a crucial difference between defying common belief, which great scientific breakthroughs do, and defying reasoning, which they don't do. Reasoning is what shows that the old theory did not have the explanatory power of the new theory.

Re: Does Diversity Trump Ability? An Example of the Misuse of Mathematics [pdf]

#57

Post by SnacksOnAPlane »

DanBC wrote: post #38
kenjackson wrote: post #7

Earlier quoted context omitted.

It also seems to defy common sense. How many top ACM programming teams randomly pick programmers from the college? How many great bball teams are randomly picked from players? There are few activities, where excellence is easily measured, where randomly picking participants results in superior results.

Moneyball shows us that all that knowledge and experience used to pick a baseball team was wrong and that people should ignore their "common sense" (which is usually just another word for "cognitive bias") and should use hard data. In the absence of hard data just picking a team randomly froma pool of qualifying players seems to me like it would be as good as pickping players based on the team-picker's experience of…

But you said "qualifying players", which implies that there is some qualifier. What is that qualifier?

And Moneyball didn't show us that all knowledge and experience was wrong. We didn't all of a sudden start recruiting marine biologists to become baseball players. The old "common sense" still stood. It's just that resources were reallocated in a very technical, wonkish way.

It's not like someone would look at you like you were crazy if you said "hey, we should pay more attention to on-base percentage than we do now, and maybe we could win with lower salaries". It was, at best, a minor revolution in baseball asset allocation.

Re: Does Diversity Trump Ability? An Example of the Misuse of Mathematics [pdf]

#58

Post by jev »

dxbydt wrote: post #6
jev wrote: post #4

Earlier quoted context omitted.

Probably because the mathematicians don't seem to have the ability to explain why it is not sound without devolving into obscure symbols and jargon.

If this was html & written to the point instead of stuffed in a pdf & written up in this roundabout manner, it would be on top of HN with 100+ votes :) I read the whole pdf but here's the TL:DR; anyways - Randomization improves algorithms. This is so obvious to CS folks its taught in basic cs101 - the ones i'm familiar with are where you pick a random pivot element for quicksort, or say the one where you draw a circl…

I also read the paper. I didn't have any trouble understanding it. The point is that it can be explained 10x better in 10x less space, just like you did.
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