
Understanding is a poor substitute for convexity (2012) - alrex021
https://www.edge.org/conversation/nassim_nicholas_taleb-understanding-is-a-poor-substitute-for-convexity-antifragility
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jjk166
"The point we will be making here is that logically, neither trial and error
nor "chance" and serendipity can be behind the gains in technology and
empirical science attributed to them. By definition chance cannot lead to long
term gains (it would no longer be chance); trial and error cannot be
unconditionally effective: errors cause planes to crash, buildings to
collapse, and knowledge to regress."

This is an extremely flawed initial assumption. There is no requirement for
chance to be centered around zero. Consider rolling a dice: sometimes you'll
get more than the mean, sometimes less, but you'll never roll a negative
number. You can certainly win on chance in the long run, that's the foundation
of casinos and insurance companies. It's hard to imagine a scenario where
trial and error can possibly lead to knowledge regressing.

Consider randomly digging holes in the ground: after enough holes you will
eventually strike gold, and you will never lose physical gold in the process.
However, you may lose significant time, wealth, and effort that could have
been better converted to gold. The optimal way to strike gold is not to dig
more, shallower holes, but to learn enough geology to understand where gold is
likely to be found and concentrate your prospecting there.

No experiment could ever possibly hurt scientific knowledge. People tinkering
will certainly make occasional discoveries. In a brand new field with a lot of
low hanging fruit, these discoveries will be numerous and the cost will be
low. But in a developed field where people have a good idea where the
remaining discoveries are likely to be found and the effort to conduct such
experiments is substantial, targeted approaches become optimal. Reducing the
unit cost of experiments is always nice, but is not generally feasible. This
strategy of "convexity" is a very poor substitute in the real world for
understanding.

~~~
skybrian
Yeah, it's badly written in a way to provoke controversy, but fundamentally,
I'm not sure there's any real disagreement here?

In simple terms, he's just saying that it needs to be safe to take chances in
order for it to be worthwhile to take chances. As you say, science is an
example of a system where it's often safe to take chances, because you don't
risk losing any knowledge from a failed experiment. (But that doesn't mean
there are no costs! You can lose time and money. And I'll also point out that
some experiments can be dangerous.)

In any search, whether you can find something interesting is going to depend
at least partly on the landscape, so understanding the landscape better will
improve the search process, along with your estimates of whether it's worth
doing at all. Calling this property of a desirable landscape "convexity"
doesn't, in itself, help you understand the landscape, but it doesn't seem
wrong?

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DougBTX
> Yeah, it's badly written in a way to provoke controversy

I’m not sure it is worth my time to read something that is badly written to
provoke controversy, even if it does make good clickbait.

~~~
milesvp
Yeah, I used to go out of my way to follow links to Taleb’s writing, but then
I kept running into pieces like this one, where it wasn’t clear if he knew he
was fundamentally (if not subtly) wrong. He seems to welcome controversy, and
his recent childish attack on guy from 538 means I won’t give him more than a
paragragh to convince me the rest of the piece is worth my time.

~~~
solveit
I hate it when smart, competent people become famous, and a few years later
they become total loons. Happens way too often.

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rotexo
Is anyone surprised by the notion that ratcheting is critical for
consolidating gains made from chance events? I thought that was a trivial
observation (maybe my biologist bias is showing here).

~~~
repsilat
It might be obvious but worth saying anyway. Giving something a name can help
you use it as a unit of work, or reason more
effectively/accurately/mechanically.

A lot of arguments are built on abstractions like "competition" and "chance",
and having a short list of common exceptions to those heuristics on hand is
pretty useful. Now when discussing federalism in the U.S., I'll not only
wonder whether there are free-rider problems or economies of scale missed out
on, I'll also think about whether local decisions are effectively "locked in"
forever.

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pazimzadeh
“By definition chance cannot lead to long term gains (it would no longer be
chance)“

If this was modified to “chance alone” then it might be correct. The way it’s
worded now makes it sound like chance cannot contribute to long term gains,
which is clearly false. Evolution depends on chance (generation of diversity)
followed by a selection process and clearly that works pretty well.

~~~
sooheon
Yes. Chance + opportunism can lead to plenty of long term gains.

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fujimotos
The basic point of this article seems valid to me.

The point the author is trying to make is that the structure of the payoff
function matters a lot. Specifically, you need it to be convex for a try-and-
error (or random walk) process to become very rewarding.

For example, think about fuzzing C programs, which has been proven to be very
productive in terms of software security. But why is it so productive? This is
essentially because a bug in a C program can have a quite significant
implication (e.g. remote code execution), thus its payoff function is
extremely convex. If there was no such property, fuzzing just wouldn't be so
much rewarding (This explains why fuzz tests are less used for programs
written in memory-safe languages).

The author believes this idea of "convexity" can explain a broad range of
phenomena in the human world. I'm not so sure about its applicability, though.

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james_s_tayler
Isn't he basically saying the economics of research works up to a point but
there is an inflection point after which it's broken?

And he's saying you can't just keep the model as is, but you need to make
certain adjustments to the incentive structures.

It's becoming blindly obvious that this is the case in psychology at least
with the replication crisis and the "publish or perish" mentality. We can see
these things playing out.

Does the economics of the scientific machine need to be revisited and tweaked?
I'd say there is a good conversation to be had about that. I can already see a
little evidence of a minor self-correction, but given economics drives
absolutely everything then yeah I'd say it's likely there are some changes
that would produce different results that might be better than what the
current system is producing. Though it's not easy to compute ahead of time
whether changes themselves would have unintended consequences.

He probably needs to spend more time trying to explain things to 5 year olds
to offset his "I am so smrt" persona.

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zby
I think an important way to understand the optionality/convexity is to imagine
science without it. Here is a paper about that:
[https://nickbostrom.com/papers/vulnerable.pdf](https://nickbostrom.com/papers/vulnerable.pdf)
\- the idea is: what if there are inventions that could destroy our
civilisation? One example of such invention would be a bomb as powerful as an
atomic bomb - but from materials and technologies readily available to anyone.
Surely there would be terrorist/mafias/suicidal individuals who would build
and use them.

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jf-
From the title I assumed that the author was going to make a different point:
that understanding a problem does not mean that said problem can be
represented by a convex function, i.e. it still may have many local optima
that a problem solver may get stuck in, rather than a single global optimum.

So, I expected some more general point about theoretical understanding of a
thing being distinct from the actual computation of that thing, and that
theoretical understanding does not necessarily lead to optimal outcomes.

I wish he’d made that point instead.

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csomar
I'm not certain where the author wants to go with this. Comparing research
with an Airplane flight seems not correct to me.

Also

> By definition chance cannot lead to long term gains (it would no longer be
> chance)

Heh. The whole universe might be made by "chance". It is, in fact, quite
possible that the total energy of the universe is 0. Our existence is a
fluctuation.

Define long term gains. Since infinity is out of our possible reach, it is
possible (though unlikely) to make long term gains just by chance. Especially,
if you have a large audience. Some of them will get lucky.

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nt31415
"an army of pompous phrases moving across the landscape in search of an idea."

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coldtea
> _A "1/N" strategy is almost always best with convex strategies (the
> dispersion property): following point (1) and reducing the costs per
> attempt, compensate by multiplying the number of trials and allocating 1/N
> of the potential investment across N investments, and make N as large as
> possible. This allows us to minimize the probability of missing rather than
> maximize profits should one have a win, as the latter teleological strategy
> lowers the probability of a win. A large exposure to a single trial has
> lower expected return than a portfolio of small trials._

Isn't that YC Combinator in a nutshell?

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bjourne
I read the article in full but still have no idea what he is trying to say.
Perhaps someone can explain what he is talking about? Because as far as I'm
concerned its postmodernism meets statistics.

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rajacombinator
Amazing how Taleb can write such utter banalities and yet utterly believe he
is writing novel and important things.

~~~
killjoywashere
I'm not sure he thinks what he's writing is novel. But he does seem to think
it's important and if you consider his earnings as signal, he does have signal
in that direction. To whom is it important? Not academia. But probably
socially, it is. You have to convince a lot of people before you convince a
politician...

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small_mind
The writing style of this article strikes a tone that seems overly eager to
place an eloquent vocabulary on display.

    
    
      Hey guys! Look at all the
      big, big words I can use!
    
      Don’t I sound smart???
    

Seriously. It’s like they wrote, and proof read the original draft, then
performed a search/replace for any polysyllabic synonym they could
opportunistically inject.

Why do they need to _sound_ smart? Is it really because they know they’ve got
nothing to say? Is this an SAT reading comprehension test?

You could sum up the sentiment with an anaology to paraphrase the concept: “
_defensive programming is no replacement for accomplished programming skill_ ”
(to borrow a concept comparable to investing)

Big words, small mind.

~~~
dang
This comment breaks the site guidelines, which ask: " _Please don 't post
shallow dismissals, especially of other people's work. A good critical comment
teaches us something._"

Could you please not create accounts to break the guidelines with?

[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)

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sachindhar
[https://theweek.com/articles/453558/nassim-taleb-used-
hero-b...](https://theweek.com/articles/453558/nassim-taleb-used-hero-but-
today-hes-just-plain-wrong)

