Analysis of a Central Composite (Response Surface) Experiment - Review/Save Residuals Tab

Analyzing Central Composite Designs

Select the Review/save residuals tab of the Analysis of a Central Composite (Response Surface) Experiment dialog box to access options to review and save the residuals and predicted values from the analysis. Note that these results are for the currently specified model. You can specify a new model on the Model tab.

Display predicted and residual values

Click the Display predicted and residual values button to produce the Observed, Predicted and Residual Values spreadsheet, which lists these values for each case or run. If the Compute/save extended residual statistics option button is selected (see below), additional values that are shown in this spreadsheet for each case or run are the (default) 95% Prediction intervals and 95% Confidence limits, the Standardized predicted and Standardized residual scores, the Studentized residual scores, the Leverage values, the Deleted residual and Studentized deleted residual scores, Mahalanobis and Cook distance scores, the DFFITS statistic, and the standardized DFFITS statistic.

The order in which cases or runs are shown in the Observed, Predicted and Residual Values spreadsheet can be controlled through the options for Sort cases by values (see below). Note that this spreadsheet contains the values used in virtually all of the plots available on the Residual plots tab.

Sort cases by values

The Sort cases by values box provides a number of options for ordering the cases or runs shown in the Observed, Predicted and Residual Values spreadsheet. From this box, you can select options to sort the cases by Case numbers, by Observed, Predicted or Residual values, by Standard errors of predicted values, by Standardized predicted, Standardized residual or Studentized residual scores, by Leverage values, by Deleted residual, Studentized deleted residual, Mahalanobis distance, or Cook distance scores, by the DFFITS statistic, or by the Standardized DFFITS statistic. The default is to sort cases by Case numbers.

Save residuals & predicted values

Click the Save residuals & predicted values button to display a standard variable selection dialog box from which you select variables in the analysis to display along with the residuals and predicted values. After selecting variables, click the OK button to display predicted and residual values (as well as selected variables) in a standard STATISTICA spreadsheet (shown in an individual window, regardless of the settings on the Options - Output Manager tab or in the Analysis/Graph Output Manager dialog box). You can, however, add the spreadsheet to a workbook or report using the or buttons, respectively. Note that in order to save the spreadsheet, you must select the spreadsheet and use the Save or Save As commands from the File menu.

Note: if the Compute/save extended residual statistics option button is selected (see below), additional statistics that will be displayed in the spreadsheet are the (default) 95% Prediction intervals and 95% Confidence limits, the Standardized predicted and Standardized residual scores, the Studentized residual scores, the Leverage values, the Deleted residual and Studentized deleted residual scores, Mahalanobis and Cook distance scores, the DFFITS statistic, and the standardized DFFITS statistic.

Compute/save predicted and residual values only

If the Compute/save predicted and residual values only option button is selected, extended residual statistics are not listed in the Observed, Predicted and Residual Values spreadsheet and are not displayed when you click the Save residuals and predicted values button (see above).

Compute/save extended residual statistics

If the Compute/save extended residual statistics option button is selected, extended residual statistics are listed in the Observed, Predicted and Residual Values spreadsheet and are displayed when you click the Save residuals and predicted values button (see above).