Analysis of variance tables
Minitab uses the analysis of variance (ANOVA) procedure to calculate variance components, which are then used to estimate the percent variation appears later in the Gage R&R table.
The two-way ANOVA table includes terms for the participants’ heads (Subject), the technicians who take the measurements (Technician), and interaction (Subject*Technician).
If the p-value for the interaction term is greater than 0.25 (degree of insignificant effect is higher than 0.05 since the system want to make sure that the variation from interaction is very low), Minitab generates a second ANOVA table that omits the interaction term from the model. To alter the default type I error rate of 0.25, click Options and enter a new value (for example, 0.3)