In sampling, the margin of error (usually expressed in percentage points) indicates how far the sample's results can stray from the true value in the entire population For example, if a poll reports that 78% of Americans eat peanut butter and the margin of error is stated to be 3%, we can expect that the true value of peanut butter eaters is somewhere between 75% and 81% The sample is not guaranteed to be within that range, but likely to be (See confidence level)
range of uncertainty Public opinion polls generally use margin of error to indicate a 95% confidence interval, corresponding to an uncertainty range of x ± 2s [Taylor, 14]
A measure of the uncertainty in an estimate of a parameter; unfortunately, not everyone agrees what it should mean The margin of error of an estimate is typically one or two times the estimated standard error of the estimate
an index indicating the amount beyond the minimum necessary; "in engineering the margin of safety is the strength of the material minus the anticipated stress"
A range of numbers used to determine the confidence interval, usually expressed as "plus or minus and x %" Note that the margin of error is computed on sample size and is only valid if the poll was well designed and executed on a true random sample A poll with misleading questions will produce misleading results
the degree of similarity between sample results and the results from a 100 percent count obtained in an identical manner
The ± value added to and subtracted from a point estimate in order to develop a confidence interval
A measurement of the accuracy of the results of a survey Example: A margin of error of plus or minus 3 5% means that there is a 95% chance that the responses of the target population as a whole would fall somewhere between 3 5% more or 3 5% less than the responses of the sample (a 7% spread)
The sampling error of the estimated statistic The margin of error is usually expressed as half the the width of a confidence interval Examples: p' plus or minus ME Xbar plus or minus ME where ME=Margin of ErrorAudit Sample Planner develops sampling plans based on the margin of error