
Is 17 the most "random" number? - mahipal
http://scienceblogs.com/cognitivedaily/2007/02/is_17_the_most_random_number.php
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antonios
Although the computer-generated charts are statistically meaningless, the
persistence of number '17' in humans likely has its reason.

The first thing that comes to my mind is that this happens because 17 the
number from 1 to 20 that we come into most rarely. When we learn
multiplication at school, it doesn't have any factors so we tend to skip it,
and for the same reason it's rare to encounter it in various problems. This
happens also to '7', but '7' is small enough to occur in many occasions such
as counting a number of items etc. So, maybe we are more inclined to pick '17'
as 'random' because we rarely meet it. Maybe.

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spicyj
The same could be said for other primes like 13 and 19, though.

~~~
baddox
13 has pervasive cultural significance, but I agree that 19 seems as "rare" as
17. Perhaps at a glance 19 is less obviously prime than 17. Also note that 17
and 19 are both ages at which nothing really notable happens. 16 is driving
age for lots of states and 18 is a big "legal" milestone.

~~~
jarek
19 is drinking age in most of Canada.

19 feels too close to the nice, round, important 20 to count as properly
random for me.

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electromagnetic
Agreed 17 really doesn't seem to have any significance anywhere in almost any
society.

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pigbucket
I learned the truth at seventeen (<http://en.wikipedia.org/wiki/At_Seventeen>)

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detcader
My economics teacher once used the number 17 as a random number twice in one
class, without noticing.

A note on the number 7: magicians actually use the frequency of that number
being picked for their tricks. If an amateur card magician asks you to pick a
number, for example, "between 5 and 10" or the more daring "between 1 and 10"
they want you to say 7. Now that you know this, though, I'd rather you humor
us if you're ever asked..

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philh
This is a really bad analysis. I'd be willing to guess the author doesn't know
much about statistics. (Or more charitably, he's just trying too hard to write
for people who don't understand statistics.)

That said, it does look like the sample was large enough for the results to be
valid, at least for "17".

~~~
DougBTX
What's so bad about it? I thought that generating 347 random numbers was a
neat way to demonstrate the variation in a random distribution with the same
sample size actually polled.

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teaspoon
That doesn't really tell us anything about variance. After all, in that single
trial of generating 347 numbers, his computer could just as easily have spat
out a uniform distribution.*

To see variance, it would have been better to generate 347 numbers _many_
times over, then plot the standard deviation of the count of each number using
error bars.

*You can't actually evenly distribute 347 trials over the range [1,20], but you see my point.

~~~
DougBTX
_his computer could just as easily have spat out a uniform distribution_

But that's the point, isn't it? An exactly even distribution is _unlikely_. So
unlikely, that the first distribution he found was probably fine for use in
the article.

I suppose my only real point here is that error bars are boring, and it's
perfectly possible to understand what the variation in a typical random set is
by looking at the set, without having to explicitly put error bars around a
straight line.

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msbarnett
int get_random() {

    
    
        return 17; // The most random number
    
    }

~~~
fragmede
<http://www.random.org/analysis/dilbert.jpg>

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yena
That's what my old math professor always said: "Now let's pick a random
number, say 17, and ..."

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dennisgorelik
How can that knowledge (that people like 17 as a random number) be turned into
profit?

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hugh3
Easy. Make bets with strangers that you can guess the number they're thinking
of.

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archgoon
You'll lose more than half the time. If you try a more complicated betting
structure than "Bet you $5", you'll have to explain it to them, which will
make them suspicious.

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arantius
Let's assume the data in the article is perfectly representative, or that it
is chosen "almost 18" percent of the time. I'll say an even 18 to make this
easier:

"I'll bet that if you pick any random number from 1 to 20, I can guess it. If
I miss, I give you a dollar. If I get it right, you give me ten."

Over 100 trials, you would lose $1 92 times, but gain $10 18 times: net gain
of $88. It works almost all the way down to getting $5 per correct guess.

Intuition would tell the guesser that they've got a nineteen-to-one chance of
gaining a dollar. You know (in theory) they've got only slightly better than a
one-in-five chance of winning.

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paraschopra
23 is. Though I am pretty rational person, I can't seem to explain why I see
23 all around. (Guessing it is some sort of psychological bias -- but the
evidence from my everyday experience just baffles me).

See this: 23 enigma <http://en.wikipedia.org/wiki/23_enigma>

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mcantelon
I've been aware of the 23 enigma theory for ~5 years, but haven't noticed
evidence supporting it.

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chadboyda
I'm sure this has a lot more to do with "anchoring" than "random".

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chunkbot
There were 17 comments when I wrote this one. Pretty random!

