Program logic bugs vs input/environmental errors

[Joseph Rushton Wakeling via Digitalmars-d]

On Friday, 10 October 2014 at 06:28:06 UTC, Iain Buclaw via 
Digitalmars-d wrote:
> http://www.wired.com/2012/12/what-does-randomness-look-like/

... yes, allowing for the reasonable expectations one can have 
for extended runs of heads in a regular 50/50 coin-flip process.

Actually, related to that article, in my very first stats lecture 
at university, the first slide the lecturer showed us (on the 
overhead projector...) was, side by side, two patterns of dots 
each within a rectangular area.

He asked: "Do you think these points are distributed at random?"  
Well, they pretty much looked the same to the naked eye.

Then he took another transparency, which placed grids over the 
two rectangular dot-filled areas.  In one, the dots were here, 
there, with some grid squares containing no dots at all, some 
containing clusters, whatever.

In the other, every single grid square contained exactly one dot.

I still think that was one of the single most important lessons 
in probability that I ever had.