-log( Alpha ) for Stopping RuleAlpha is the threshold p-value required for a single binary or ternary partition. The p -value is the proportion of permutations of the intensity values that afford a partition with a more extreme Student t-statistic . If the p -value is greater or equal to alpha , the segment is not partitioned. The p -value is computed as the sum of the Major Arc p -value and the Minor Arc p -value.