Graphs of Input Data - Probability Plot

Ribbon bar. Select the Graphs tab. In the More group, click Input Data Graphs and from the menu, select Probability Plot.

Classic menus. From the Graphs - Graphs of Input Data submenu, select Probability Plot.

These Graphs of Input Data plots visualize normality of the distribution of the currently highlighted variable. The assumption of normality (that the data follow a normal distribution) often needs to be tested, since many statistical procedures assume that the distribution of an analyzed variable is normal. You can choose from three different types of normal probability plots to visually verify the normality of a variable when you select this option.

 Normal Probability plot  

 Half-Normal Probability plot

 Detrended Normal Probability plot  

Note that you can visually compare the normality of the values of a variable in graphs identified by a grouping variable by selecting Probability Plot By ... from the Graphs - Graphs of Input Data submenu.  

Many other types of probability plots are available in Statistica's Graphs menu graphs. In order to produce normal probability plots of the values in cases (and not variables), use either the Graphs of Block Data - Custom Graph for Entire Row or Graphs of Block Data - Custom Graph from Block by Row option from the spreadsheet shortcut menu (instead of transposing your data file). Note that if more than one row (or column) is highlighted, then a multiple normal probability plot will be produced. For a general overview of the graphics facilities in Statistica, see Graphs in Statistica.