Understanding Polling Data

Have you ever been asked to participate in one of those “national polls” used to predict everything from presidential elections to the latest trend in fashion?  No?  Me either – I have never been asked to participate in a poll but somehow they sure are able to accurately predict elections, fashion trends…you name it.

How many customer surveys do I need before I can with confidence say – I know what the total population would have said given the chance to answer?  Here is an interesting article and a sample-size calculator that I think goes a long way toward explaining sampling:


At this same site you will find a link to an easy to use sample-size calculator for those of us who are math challenged.