Interval estimate

An interval estimate reports a range of plausible values for a parameter, formed as a point estimate plus or minus a margin of error.

A point estimate gives you one number, which is almost certainly a little off; an interval estimate admits that by attaching a reach on each side. The general form is point estimate±margin of error\text{point estimate} \pm \text{margin of error}, and a confidence interval is the version that comes with a stated confidence level. For example, if 62% of a sample supports a measure and the margin of error is 4 percentage points, the interval estimate runs from 58% to 66%. Wider intervals are more likely to capture the parameter but tell you less about where it sits.

Where this comes up

More confidence intervals terms, or browse the full statistics glossary.