Model Browser User's Guide    

Design Evaluation Tool

The Design Evaluation tool is only available for linear models.

You can open the Design Evaluation tool from the Design Editor or from the Model Browser windows. From the Design Editor select Tools -> Evaluate Designs and choose the design you want to evaluate. From the Model Browser global view, you can click the  button.

In the Design Evaluation tool you can view all the information on correlations, covariance, confounding, and variance inflation factors (VIFs). You can investigate the effects of including or excluding model terms aided by this information (you must remove them in the Stepwise window). Interpretation is aided by color-coded values based on the magnitude of the numbers. You can specify changes to these criteria.

When you open the Design Evaluation tool, the default view is a table, as shown in the preceding example. You choose the elements to display from the list on the right. Click any of the items in the list described below to change the display. Some of the items have a choice of buttons that appear underneath the list box.

To see information about each display, click the  toolbar button or select View -> Matrix Information.

Table Options

You can apply color maps and filters to any items in a table view, and change the precision of the display.

To apply a color map or edit an existing one:

  1. Select Options -> Table -> Colors. The Table Colors dialog appears.
  2. Select the check box Use a colormap for rendering matrix values.
  3. Click the Define colormap button. The Colormap dialog appears, where you can choose how many levels to color map, and the colors and values to use to define the levels. Some tables have default color maps to aid analysis of the information, described below.

You can also use the Options -> Table menu to change the precision (number of significant figures displayed) and to apply filters that remove specific values or values above or below a specific value from the display.

The status bar at bottom left displays whether color maps and filters are active in the current view.

When evaluating several designs, you can switch between them with the Next design toolbar button or the Design menu.


  PRESS Statistic Design Matrix