| outlier An entry in a set of statistical data which lies a long way from any pattern apparent in the rest of the data-set. The presence of an outlier suggests two possibilities which warrant further investigation. One is that something really exceptional occurred to cause it; such an occurrence is a shock. The other possibility is that the outlier occurred because of a mistake in recording or processing the data. Some statistical programmes exclude outliers in calculating trends or regressions; others include them but draw the user's attention to them. |