Frequency Tables - Descr. Tab

Select the Descr. tab of the Frequency Tables dialog box to access options to review descriptive statistics for the selected variables as well as a variety of plots that aid in visualizing the distribution of the variables.

Descriptive statistics

Click the Descriptive statistics button to produce a spreadsheet of descriptive statistics for the selected Variables.

The manner in which data are processed in the computation of descriptive statistics depends on the Categorization method for tables & graphs (see the Advanced tab). Specifically:

• If the Step size option button is selected and a user-specified minimum is specified, all cases with values less than the minimum will be ignored;
• If the Integer categories option button is selected, all non-integer values will be ignored;
• If the Specific grouping codes (values) option button is selected, all values that do not match any of the selected integer codes will be ignored;
• If the User-specified categories option button is selected, the Descriptive statistics button will be dimmed (because complex compound conditions can be specified to assign cases to categories which could result in a case being eligible for more than one category). A case will be assigned to the first User-specified interval to which it "fits" and Descriptive statistics will not be calculated for these intervals (see also Define Categories).

In all cases, missing data will either by deleted casewise or pairwise, depending on the selection in the MD deletion group box.

Box & whisker plot for all variables

1. Click the Box & whisker plot for all variables button to produce a box and whisker plot for the selected Variables. The box and whisker plot will summarize each variable by three components:
   • A central line to indicate central tendency or location;
   • A box to indicate variability around this central tendency;
   • Whiskers around the box to indicate the range of the variable.
2. Click this button to display the Box-Whisker Type dialog box.
3. Use the options to specify a box and whisker type plot.

   Normal probability plots

Click the Normal probability plots button to produce a cascade of normal probability plots for the selected Variables, one plot per selected variable.

For more information on how the standard normal probability plot is constructed, see Normal Probability Plots.

Half-normal probability plots

Click the Half-normal probability plots button to produce a cascade of half-normal probability plots for the selected Variables, one plot per selected variable.

For more information on how the half-normal probability plot is constructed, see Half-Normal Probability Plots.

Detrended normal probability plots

Click the Detrended normal probability plots button to produce a cascade of detrended normal probability plots for the selected Variables, one plot per selected variable.

For more information on how the detrended normal probability plot is constructed, see Detrended Normal Probability Plots.

3D histograms, bivariate distributions

1. Click the 3D histograms, bivariate distributions button to produce a cascade of 3D histograms for selected pairs of variables, one plot per pair. A standard variable selection dialog box will  display.
2. Select two lists of variables (from among those originally selected via the Variables option).

3D histograms will be produced for each variable in the first list with each variable in the second list.