Summary Statistics for Scale Variables and Categorical Custom Totals

In addition to the counts and percentages available for categorical variables, the following summary statistics are available for scale variables and as custom total and subtotal summaries for categorical variables. These summary statistics are not available for multiple response sets or string (alphanumeric) variables.

Mean. Arithmetic average; the sum divided by the number of cases.

Median. Value above and below which half of the cases fall; the 50th percentile.

Mode. Most frequent value. If there is a tie, the smallest value is shown.

Minimum. Smallest (lowest) value.

Maximum. Largest (highest) value.

Missing. Count of missing values (both user- and system-missing).

Percentile. You can include the 5th, 25th, 75th, 95th, and/or 99th percentiles.

Range. Difference between maximum and minimum values.

Standard error of the mean. A measure of how much the value of the mean may vary from sample to sample taken from the same distribution. It can be used to roughly compare the observed mean to a hypothesized value (that is, you can conclude that the two values are different if the ratio of the difference to the standard error is less than –2 or greater than +2).

Standard deviation. A measure of dispersion around the mean. In a normal distribution, 68% of the cases fall within one standard deviation of the mean and 95% of the cases fall within two standard deviations. For example, if the mean age is 45, with a standard deviation of 10, 95% of the cases would be between 25 and 65 in a normal distribution (the square root of the variance).

Sum. Sum of the values.

Sum percentage. Percentages based on sums. Available for rows and columns (within subtables), entire rows and columns (across subtables), layers, subtables, and entire tables.

Total N. Count of non-missing, user-missing, and system-missing values. Does not include cases in manually excluded categories other than user-missing categories.

Valid N. Count of non-missing values. Does not include cases in manually excluded categories other than user-missing categories.

Variance. A measure of dispersion around the mean, equal to the sum of squared deviations from the mean divided by one less than the number of cases. The variance is measured in units that are the square of those of the variable itself (the square of the standard deviation).

For categorical variables, the table must include totals or subtotals to display custom summary statistics. See the topic Custom Total Summary Statistics for Categorical Variables for more information.

Stacked Tables

Each table section defined by a stacking variable is treated as a separate table, and summary statistics are calculated accordingly.