The concept of margin of error has been much discussed here in the last few days since clearly the morons who babble on TV don't get it. Now I know must people don't want to delve into the dark arts of the Integral Calculus, but TPM has a nice little explanation that makes it very clear what this is all about.

Margin of Errorhttp://talkingpointsmemo.com/...

In public opinion surveying, the margin of error refers to the expected range of variation in a poll, if it were to be conducted multiple times under the same procedures. This is not necessarily indicative of a true result, but establishes a statistical average within which most polls will line up. As an example, if a Democratic candidate has 47% in a poll and the Republican 45%, with a Â±4% margin of error, the poll could potentially show the Democrat as high as 51% or as low as 43%, and the Republican ranging from 41%-49%, if the poll were repeated. In statistical terms, the margin of error is typically established for a 95% confidence interval, meaning that the officially listed variation will occur in 19 out of 20 times that a poll is conducted -- but also that in 1 of 20 cases, a pollster will produce a result that lies far outside the norm.

## Comment Preferences