2.42.3.1.4 The Analyze Mixure Design Dialog Box

Contents

Supported Information

To open the Analyze Design dialog

Topics for Further Reading:


Model

Response Select the column containing the measured outcome variable.
Model Terms Specify which effects to include in the fitted model. Click the + button to open a dialog to select model terms

In the opened dialog, you can choose from the term list below, add or remove the terms from the right panel, and click the OK button to define the model.

  • Generate Terms by Model Type
    This dropdown auto-populates the Selected Terms list based on standard Scheffé mixture model orders:
  • Linear
  • Quadratic
  • Special Cubic
  • Full Cubic
  • Special Quartic
  • Full Quartic
  • Include Inverse Component Terms
    When checked, this adds inverse terms such as 1/A, 1/B, 1/C to the available terms.
  • Include Mixture Amount Terms Up through Order
    Available only for mixture-amount designs (where the total amount of the mixture varies in addition to the proportions). The dropdown specifies how the total amount enters the model
  • Include Process Variable Terms Up through order
    Available only if design is created with process variables. The option controls how non-mixture factors (process variables) are incorporated into the regression model alongside your mixture components.
Include Blocks in the Model Toggle whether block terms are included as fixed effects in the regression model.
Analyze Components in Specifies how mixture components are represented in the model:
  • Proportions
    Uses the actual component proportions.
  • Pseudo-components:
    Transforms the component proportions based on the specified lower and upper bounds

Stepwise

Perform stepwise regression to identify the best subset of the model. Four selection methods are available. Please refer to the Stepwise Regression for Analyze Design page for more details

Method Select the stepwise regression methods
  • None
  • Stepwise
  • Forward Selection
  • Backward Elimination
Alpha to Add The significance threshold for adding a term to the model. A candidate term enters the model only if its p-value is below this threshold.
Alpha to Remove The significance threshold for removing a term already in the model. A term is removed if its p-value exceeds this threshold.
Show Model Selection Details Displays the step-by-step log of the selection process in the output.

Quantities

Select which numerical results are reported after fitting the model. Refer to the interpreting results page for details of the statistics

Coefficients Table Selects the statistics displayed for each model term. Refer to the interpreting results page for details of the statistics
  • Coefficients
  • Standard Error
  • Confidence Limits
  • t-Value
  • Prob>|t|
  • VIF
Confidence Level (%) Sets the confidence level for the interval estimates (default is 95%). A higher level produces wider intervals but greater confidence that the true value is captured.
Regression Equation When enabled, outputs the fitted regression equation. This lets you predict the response by plugging in factor values.
ANOVA Table When enabled, displays the Analysis of Variance table, which partitions the total variation into model, residual, and lack-of-fit components. It provides the overall F-test and p-value to assess whether the model explains a significant portion of the variation.
Fit Statistics These metrics summarize how well the model fits the data. Refer to the interpreting results page for details of the fit statistics
  • R-Sqaure
  • Adj.R-Sqaure
  • Residual Sum of Square
  • Predicted R-Square
  • PRESS
  • Root-MSE (SD)

Diagnotics

The Diagnostics tab controls which residual and fitted-value outputs are generated for checking model assumptions and spotting unusual observations.

Refer to the diagnotics section in the interpreting results page for details of the fitted results and residuals

Fitted Values When enabled, reports the predicted response value for each run based on the fitted model. These are the values the model expects, used to compare against actual observations.
Residuals Select which type of residual values to be output
  • Regular
  • Standardized
  • Studentized
  • Studentized Deleted

Prediction

The Prediction tab controls whether to generate the prediction worksheet for calculating response values and their associated uncertainty intervals from specified factor values.

Refer to the Model Prediction - Find Y from X page for details on the generated worksheet.

Find Y from X Toggles the prediction calculation on or off. When enabled, a worksheet named DOEFindYfromX is generated. In the worksheet, enter factor values into the respective columns, the predicted response (Y) are calculated automatically.
95% Confidence Limits for Predicted Y When checked, the report includes the 95% confidence interval for the mean response at each set of factor levels
95% Prediction Limits for Predicted Y When checked, the report includes the 95% prediction interval for an individual future observation.

Plots

The Plots tab lets you select which diagnostic and exploratory graphs to generate from the fitted model.

Plots Select the plots to generate from the fitted model. Refer to the Plots in DOE page for details of the plots
  • Fittted Plot
  • Residual Plot
  • Contour Plot
  • Surface Plot
Residual Type Choose the residual type to be used for the residual plot. Refer to the diagnotics section in the interpreting results page for details of the residuals
  • Regular
  • Standardized
  • Studentized
  • Studentized Deleted
Settings of Contour and Surface Plot Available only if Contour Plot or Surface Plot is selectedf from the Plots control

The section enables you to select which two continuous factors to be used as X/Y axes and define the specific operating conditions for the contour or surface slice

  • Component for X / Y / Z Axis
    Select components for the X, Y and Z axes
  • Component Unit
    Determines the scale used to label the plot axes and report component levels.
  • Amount: Displays the actual physical quantities
  • Proportion: Displays each component as a fraction of the total mixture (values from 0 to 1).
  • Pseudo-component: Displays values transformed to the pseudo-component scale, which maps the lower and upper bounds of each component to 0 and 1.

Dialog Theme

Save and load the settings of the dialog. Use this to store frequently used factor configurations, design options, or output preferences, then recall them for future designs without re-entering all values.