**The **
**confidence level**** indicates a degree of certainty (as
a percentage) that that the results of a study fall within a given range of
values. Typical confidence levels are 95% and 99%.**

**The ****confidence
interval**** (margin of error) is a plus-or-minus percentage that is
a range within the confidence level. For example, if a 5% confidence interval
is used, and 50% of the sample gives a specific answer for a question, the
actual result for that question falls between 45% and 55% (50 ± 5).**

When using confidence level and confidence interval together, researchers using a 95% confidence level with a ±5% confidence interval can say that they are 95% sure their results are accurate within ±5 percent.