On 10/10/2014 05:31 AM, Joseph Rushton Wakeling wrote:
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.
I like that. I actually have a similar classroom probability story too
(involving one of the best teachers I ever had):
As part of a probability homework assignment, we were asked to flip a
coin 100 times and write down the results. "Uhh, yea, there's no way I'm
doing that. I'm just gonna write down a bunch of T's and F's."
Having previously played around with PRNG's (using them, not actually
creating them), I had noticed that you do tend to get surprisingly long
runs of one value missing, or the occasional clustering. I carefully
used that knowledge to help me cheat.
During the next class, the teacher pointed out that "I can tell, most of
you didn't actually flip a coin, did you? You just wrote down T's and
F's..." Which turned out to be the whole *point* of the assignment.
Deliberately get students to "cheat" and fake randomness - poorly - in
order to *really* get them to understand the nature of randomness.
Then he turned to me and said, "Uhh, Nick, you actually DID flip a coin
didn't you?" Hehe heh heh. "Nope :)" I got a good chuckle out of that.
