Please refer to the following information,
Extreme values,
stragglers and outliers
Extreme values are defined as observations
in a sample, so far separated in value from
the remainder as to suggest that they may
be from a different population, or the
result of an error in measurement (6).
Extreme values can also be subdivided into
stragglers, extreme values detected
between the 95% and 99% confidence
and outliers; extreme values at >
99% confidence level.