# Codebook Statistics Tab

The Statistics tab allows you to control the summary statistics that are included in the output, or suppress the display of summary statistics entirely.

Counts and Percents

For nominal and ordinal variables, multiple response sets, and labeled values of scale variables, the available statistics are:

Count. The count or number of cases having each value (or range of values) of a variable.

Percent. The percentage of cases having a particular value.

Central Tendency and Dispersion

For scale variables, the available statistics are:

Mean. A measure of central tendency. The arithmetic average, the sum divided by the number of cases.

Standard Deviation. A measure of dispersion around the mean. In a normal distribution, 68% of cases fall within one standard deviation of the mean and 95% of 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.

Quartiles. Displays values corresponding to the 25th, 50th, and 75th percentiles.

Note: You can temporarily change the measurement level associated with a variable (and thereby change the summary statistics displayed for that variable) in the source variable list on the Variables tab.

To Select Codebook Statistics

This feature requires the Statistics Base option.

- From the menus choose:
- Click the Statistics tab.