The Web on Sampling
Surfstat
©
on non-random samples
http://surfstat.newcastle.edu.au/surfstat/main/2-1-1.html
By the Annenberg/CPB Project ©
How Random Is Random?
http://www.learner.org/exhibits/statistics/howrandom2.html
What Can Go Wrong?
http://www.learner.org/exhibits/statistics/gowrong2.html
How Polls Are Conducted
by The Gallup Organization © at
http://www.gallup.com/The_Poll/hpac.asp