Outlier

An outlier is a data point that is very different from most of the other data points. For example, if the mean math test score for a class is 45%, and one student gets 98%, that student could be considered an outlier. It is up to the analyst to decide exactly how far out a data point needs to be before it is called an outlier.

Outlier data points should be checked carefully to make sure there was not an error in data entry.