Including Missing Values in Tables

  1. Open the table builder (Analyze menu, Tables, Custom Tables).
  2. Right-click Variable with missing values in the table preview on the canvas pane and select Categories and Totals from the pop-up menu.
  3. Click (check) Missing Values in the Categories and Totals dialog box, and then click Apply.

    Now the table preview includes a Missing Values category. Although the table preview displays only one category for missing values, all user-missing categories will be displayed in the table.

  4. Right-click Variable with missing values in the table preview on the canvas pane again and select Summary Statistics from the pop-up menu.
  5. In the Summary Statistics dialog box, click (check) Custom Summary Statistics for Totals and Subtotals.
  6. Select Valid N in the custom summary Statistics list and click the arrow to add it to the Display list.
  7. Do the same for Total N.
  8. Click Apply to Selection, and then click OK in the table builder to create the table.
    Figure 1. Table with missing values
    Table with missing values

    The two defined user-missing categories--Don't know and Not applicable--are now displayed in the table, and the total count is now 9 instead of 7, reflecting the addition of the two cases with user-missing values (one in each user-missing category). The column percentages are also different now, because they are based on the number of non-missing and user-missing values. Only system-missing values are not included in the percentage calculation.

    Valid N shows the total number of non-missing cases (7), and Total N shows the total number of cases, including both user-missing and system-missing. The total number of cases is 10, one more than the count of non-missing and user-missing values displayed as the total in the Count column. This is because there's one case with a system-missing value.

  9. Open the table builder (Analyze menu, Tables, Custom Tables).
  10. Right-click Variable with missing values in the table preview on the canvas pane and select Summary Statistics from the pop-up menu.
  11. Select Column Valid N % in the top Statistics list (not the custom summaries for totals and subtotals) and click the arrow to add it to the Display list.
  12. Do the same for Column Total N %.
  13. You can also add them both to the list of custom summary statistics for totals and subtotals.
  14. Click Apply to Selection, and then click OK to create the table.
Figure 2. Table with missing values and valid and total percentages
Table with missing values and valid and total percentages
  • Column N % is the percentage in each category based on the number of non-missing and user-missing values (since user-missing values have been explicitly included in the table).
  • Column Valid N % is the percentage in each category based on only the valid, non-missing cases. These values are the same as the column percentages were in the original table that did not include user-missing values.
  • Column Total N % is the percentage in each category based on all cases, including both user-missing and system-missing. If you add up the individual category percentages in this category, you'll see that they add up to only 90%, because one case out of the total of 10 cases (10%) has the system-missing value. Although this case is included in the base for the percentage calculations, no category is provided in the table for cases with system-missing values.