Identify Unusual Cases Output

List of unusual cases and reasons why they are considered unusual. This option produces three tables:

  • The anomaly case index list displays cases that are identified as unusual and displays their corresponding anomaly index values.
  • The anomaly case peer ID list displays unusual cases and information concerning their corresponding peer groups.
  • The anomaly reason list displays the case number, the reason variable, the variable impact value, the value of the variable, and the norm of the variable for each reason.

All tables are sorted by anomaly index in descending order. Moreover, the IDs of the cases are displayed if the case identifier variable is specified on the Variables tab.

Summaries. The controls in this group produce distribution summaries.

  • Peer group norms. This option displays the continuous variable norms table (if any continuous variable is used in the analysis) and the categorical variable norms table (if any categorical variable is used in the analysis). The continuous variable norms table displays the mean and standard deviation of each continuous variable for each peer group. The categorical variable norms table displays the mode (most popular category), frequency, and frequency percentage of each categorical variable for each peer group. The mean of a continuous variable and the mode of a categorical variable are used as the norm values in the analysis.
  • Anomaly indices. The anomaly index summary displays descriptive statistics for the anomaly index of the cases that are identified as the most unusual.
  • Reason occurrence by analysis variable. For each reason, the table displays the frequency and frequency percentage of each variable's occurrence as a reason. The table also reports the descriptive statistics of the impact of each variable. If the maximum number of reasons is set to 0 on the Options tab, this option is not available.
  • Cases processed. The case processing summary displays the counts and count percentages for all cases in the active dataset, the cases included and excluded in the analysis, and the cases in each peer group.

How to obtain tabular output

  1. From the menus choose:

    Data > Identify Unusual Cases...

  2. In the Identify Unusual Cases dialog box, click the Output tab.