This is a nice write down:

 http://www.chris-granger.com/2014/03/27/toward-a-better-programming/

with a nice demo of a prototype:

 https://www.youtube.com/watch?v=L6iUm_Cqx2s

Luckily, the horrible C++ code computing standard deviation in the article can be written quite elegantly and directly in Pharo:

| input |
input := #(2 4 4 4 5 5 7 9).
(((input - input average) raisedTo: 2) sum / (input size - 1)) sort.

Sven