Minitab provides a Pareto chart of the effects to visualize the results from the coefficient and ANOVA tables. For the terms in the model, this graph allows you to compare the relative magnitude of the effects and to evaluate their statistical significance. Minitab draws the Pareto chart when the model leaves at least 1 degree of freedom for error.
The threshold for statistical significance depends on the significance level (denoted by α or alpha). Unless you use a stepwise selection method, the significance level is 1 minus the confidence level for the analysis. For more information on how to change the confidence level, go to Select the options for Fit Regression Model. If you use backwards selection or stepwise selection, the significance level is the significance level where Minitab removes a term from the model, known as Alpha to remove. If you use forward selection, the significance level is the significance level where Minitab adds a term to the model, known as Alpha to enter. For more information on the choices for the stepwise methods, go to Perform stepwise regression for Fit Regression Model.