Percent Outlier Treatment

For this treatment, an outlier is an attribute with a value in the Lower Tail Percent or Upper Tail Percent. If both percents equal 5 (the default), the outliers are the bottom 5% and the top 5% of the values. The two percents do not have to be equal.

You must also specify what value to replace outliers with. You can either replace outliers values with nulls (that is, "throw the values away") or you can replace them with edge values. In the example above, the edge values are that value L for which 5% of the values are below it and that value Mfor which 5% of the values are greater than it. If you specify Replace with edge values, all values less than L are replaced with L and all values greater than M are replaced with M. The default is to Replace with nulls.