The Problem With Polling, from Bill Rafter
The problem with polling is because of the response rate. A generation or two ago people were honored that someone would solicit their opinion. No so today, for whatever reason. Two days ago the Pew Foundation revealed the percentage of those persons contacted who are willing to give their opinions. Take a guess as to what that percentage is: According to Pew, their "success rate" is nine percent, or one out of every eleven persons they speak with. Thus they cannot get a reasonable random sample and the Central Limit Theorem does not apply. Therefore most polls are GIGO.