A proper law

[Peter Tomlinson]

The key phrase in my contribution was "check .. for patterns".. Initially,
when getting into the technology of random number generation, I too was
surprised by the clumps and empty regions.

Peter
----- Original Message -----
From: "Ian G Batten" <I.G.Batten@ftel.co.uk>
To: <ukcrypto@chiark.greenend.org.uk>
Sent: Thursday, March 06, 2003 9:05 AM
Subject: Re: A proper law


> On Thu, 06 Mar 2003, Peter Tomlinson wrote:
>
> > In my experience, the processing uses a fixed algorithm, and is not an
> > attempt to spot non-randomness. One practitioner in this field told me
to
> > print out the bit stream as a 2D plot (e.g. just fill a page with the
bits)
> > and check it by eye for patterns.
>
> That's bad advice (in those bald terms, at least).  There are repeatable
> experiments which take 1000 random points on a page, and get people to
> compare them with 1000 points which are generated by plotting a regular
> grid and then purturbing each point by a random distances, whose mean
> value is less than the initial grid spacing.  People tend to see the
> latter as ``more random'', as it evinces fewer clumps and empty
> regions.
>
> ian
>
>
>
>