The interquartile distance is used to find outliers in the local Moran test. The interquartile distance is the difference between the values for the 25th-percentile and the 75th-percentile of the test statistic.
To obtain these values, ClusterSeer orders the test statistics from smallest to largest. The 25th-percentile value i the test statistic that divides the ordered set such that 25% of the statistics are smaller and 75% are greater. The 75th-percentile value is the test statistic that divides the ordered set such that 75% of the statistics are smaller and 25% are greater. If the number of test statistics cannot be evenly divided by 2, these values are calculated as the mean of the two test statistics closest to the appropriate position.
ClusterSeer then multiplies the interquartile distance by 1.5. Any values farther from the median than 1.5 times the interquartile distance are considered outliers.
