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Re: One _never_ knows if data is truly random or not.

From Fabian Russell <fb@zen.info>
Newsgroups sci.physics, comp.os.linux.advocacy
Subject Re: One _never_ knows if data is truly random or not.
Date 2016-07-12 14:33 +0000
Organization NewsGuy - Unlimited Usenet $23.95
Message-ID <nm2v310306u@news4.newsguy.com> (permalink)
References <87b8a1c6-e14c-47f7-9647-52f4ab874054@googlegroups.com> <nm1ang0t2g@news6.newsguy.com> <Jeff-Relf.Me@Jul.11{5.48P.Seattle.2016}>

Cross-posted to 2 groups.

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On Mon, 11 Jul 2016 17:48:23 -0700, Jeff-Relf.Me wrote:

>
> One _never_ knows if data is truly random or not;
>

That statement implies that true randomness exists but
we, as human observers, cannot describe it. 

Randomness is a human intellectual construct and hence
depends on a particular _definition_.

As a result, there may be different types of randomness
depending on different circumstances.

For most scientific purposes a sequence is random if it
passes a plethora of accepted statistical tests.

Which of the two following sequences is "more" random:

5 1 9 7 2 3 8 4 7 3 

5 4 9 7 7 6 5 3 3 8

A lot of people would claim that the first sequence
appears to be more random because it contains no successive
repeats of the same number and there are no contiguous pairs.

But the second sequence is actually more plausibly the result
of a "random" process because successive repeats and contiguous
pairs (or triples) are not outlawed in randomness.  Indeed, the
first sequence seems less plausible as being random and seems
specially designed to avoid successive repeats as well as contiguous
numbers.  In other words, the first sequence seems to be the result
of a process that takes previous values into account.

Randomness implies only independence and not a particular
patterning.

Neither sequence, however, is long enough to make any valid statistical tests.

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Thread

Compression of random binary data jonas.thornvall@gmail.com - 2016-07-11 10:50 -0700
  Re: Compression of random binary data xxein1@att.net - 2016-07-11 13:12 -0700
  Re: Compression of random binary data Sergio <invalid@invalid.com> - 2016-07-11 15:42 -0500
  Re: Compression of random binary data Double-A <double-a3@hush.com> - 2016-07-11 13:58 -0700
    Re: Compression of random binary data Poutnik <poutnik4nntp@gmail.com> - 2016-07-11 23:12 +0200
  Re: Compression of random binary data "nuny@bid.nes" <Alien8752@gmail.com> - 2016-07-11 15:20 -0700
    Re: Compression of random binary data Sergio <invalid@invalid.com> - 2016-07-11 21:29 -0500
  Re: Compression of random binary data Lofty Goat <rlwatkins@gmail.com> - 2016-07-11 17:48 -0500
  Re: Compression of random binary data Fabian Russell <fb@zen.info> - 2016-07-11 23:39 +0000
    Re: One _never_ knows if data is truly random or not. Fabian Russell <fb@zen.info> - 2016-07-12 14:33 +0000
      Re: One _never_ knows if data is truly random or not. Poutnik <poutnik4nntp@gmail.com> - 2016-07-12 18:37 +0200
    Re: One _never_ knows if data is truly random or not. benj <benj@nobody.net> - 2016-07-12 19:26 -0400
  Re: Compression of random binary data Sylvia Else <sylvia@not.at.this.address> - 2016-07-12 15:20 +1000
    Re: Compression of random binary data Double-A <double-a3@hush.com> - 2016-07-12 13:29 -0700
      Re: Compression of random binary data Sylvia Else <sylvia@not.at.this.address> - 2016-07-13 16:29 +1000
  Re: Compression of random binary data Michael J. Strickland <michael06582@comcast.net> - 2016-07-14 00:54 -0400

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