Displaying Patterns of Missing Values

You can choose to display various tables showing the patterns and extent of missing data. These tables can help you identify:

  • Where missing values are located
  • Whether pairs of variables tend to have missing values in individual cases
  • Whether data values are extreme

Display

Three types of tables are available for displaying patterns of missing data.

Tabulated cases. The missing value patterns in the analysis variables are tabulated, with frequencies shown for each pattern. Use Sort variables by missing value pattern to specify whether counts and variables are sorted by similarity of patterns. Use Omit patterns with less than n % of cases to eliminate patterns that occur infrequently.

Cases with missing values. Each case with a missing or extreme value is tabulated for each analysis variable. Use Sort variables by missing value pattern to specify whether counts and variables are sorted by similarity of patterns.

All cases. Each case is tabulated, and missing and extreme values are indicated for each variable. Cases are listed in the order they appear in the data file, unless a variable is specified in Sort by.

In the tables that display individual cases, the following symbols are used:

+. Extremely high value

-. Extremely low value

S. System-missing value

A. First type of user-missing value

B. Second type of user-missing value

C. Third type of user-missing value

Variables

You can display additional information for the variables that are included in the analysis. The variables that you add to Additional Information for are displayed individually in the missing patterns table. For quantitative (scale) variables, the mean is displayed; for categorical variables, the number of cases having the pattern in each category is displayed.

  • Sort by. Cases are listed according to the ascending or descending order of the values of the specified variable. Available only for All cases.

To Display Missing Value Patterns

This feature requires the Missing Values option.

  1. From the menus choose:

    Analyze > Missing Value Analysis...

  2. In the main Missing Value Analysis dialog box, select the variable(s) for which you want to display missing value patterns.
  3. Click Patterns.
  4. Select the pattern table(s) that you want to display.