3D Box Plots - Advanced Tab

Graphical Analytic Techniques

Select the Advanced tab of the 3D Box Plots Startup Panel to choose variables, graph types, grouping intervals, and a variety of other options to create a box plot.

Variables. Click the Variables button to display a standard variable selection dialog box, in which you select the grouping and dependent variables for the graph. The selections made will be displayed below the Variables button.

Graph type. Select the type of 3D box plot to be plotted. Click a link below for a brief description of that type of graph.

Grouping intervals. Use the options in this group box to choose the method of categorization for each of the selected variables. For more information about the methods, see Method of Categorization.

Graph icon. The graph icon in the middle of the tab represents the currently selected Graph type, as well as the selection of values for the Middle point and Whiskers. The graph icon previews these three selections.

Middle point. In box and whisker plots, first select the desired middle point to be represented by the selected style (point or line) in these plots (the mid-point can be either the Mean or Median of the selected variable). The selection of whisker types depends on the selections made in this group box.

Pooled variance. When you select the Mean as the middle point, you can choose to use the pooled variance of the variables when calculating the ranges by selecting the Pooled variance check box. Clear this check box if you want to use separate variance estimates for each variable.

Whisker. The selection of whisker types (or values) available depends on the selections made in the Middle Point group box.

Value. If you selected the Median as the middle point, the range (whiskers) can be represented by Percentiles or the Min-Max values of the selected variable, a specified Constant value, or Non-Outlier Range.

If you selected Mean as the middle point, the range (whiskers) can be represented by the Std. Dev., Std. Error, or Min-Max values of the selected variable, Non-Outlier Range, or a specified Constant value (when you want a fixed size box around the median).

Outliers and extreme values are not displayed in the 3D box plot; however, if you select Non-outlier range, the range will be computed as in 2D Box Plots using the outlier coefficient of 1.5.

Coefficient. You can also specify a Coefficient by which the selected range value will be multiplied (by default, the Coefficient is equal to 1). In most typical applications the coefficient should be set to 1 when the value of the whisker is Min-Max or Non-outlier range. If Median is specified as the Middle point, and Percentiles is specified as the Value, the Coefficient entered must be between 0.01 - 50.0. If Mean is specified as the Middle point, and Conf. Interval is specified as the Value, the Coefficient entered must be between 0.15 - 0.9999.

Trim distrib. extremes. Use this box to specify the percent of cases to be "trimmed" from the extremes (i.e., tails) of the distribution of cases for the selected variable. For example, if you specify 10%, for a variable with 100 cases, STATISTICA will remove the 10 lowest value cases and the 10 highest value cases from the distribution, and only plot the 80 cases in between. For example, if you use this box for a mean-based box plot, so-called "trimmed means" will be plotted.

Statistics. You can include a variety of statistics as footnotes in the graph by selecting one or more of the statistics listed in this group box.

Kruskal-Wallis test. Select this check box to include the results of the Kruskal-Wallis test (a nonparametric alternative to the between group ANOVA) in the footnote section of the graph.

F test and p (ANOVA). Select this check box to include the results (F-statistic and p-value) of the test for equal variances in the footnote of the graph.