Inferential Statistics

Margin of Error

The margin of error is calculated as 2 * standard error.

That is, on the standard error page of this site, I described how to use a standard error to calculate a confidence interval for a mean:

confidence interval = observed mean ± 2 * standard error

The portion of the formula that is "2 * standard error" is called the "margin of error." Confusing? Needless terminology? Hey, don't blame me. I didn't create these traditional terms.