Use a Pareto chart of the effects to compare the relative magnitude and the statistical significance of both main and interaction effects. Minitab displays the:

·    absolute value of the unstandardized effects when there is not an error term

·    absolute value of the standardized effects when there is an error term

Minitab plots the effects in decreasing order of the absolute value of the effects. The reference line on the chart indicates which effects are significant. When your model contains an error term, by default, Minitab uses an a-level of 0.05 to draw the reference line. With no error term, Minitab uses Lenth's method to draw the reference line.

For the insulation data, there are four significant effects (a = 0.05). These significant effects include all four main effects - material type (A), injection pressure (B), injection temperature (C), and cooling temperature (D)

In addition, you can see that the largest effect is injection pressure (B) because it extends the farthest. The effect for the injection pressure by cooling temperature interaction (BD) is the smallest because it extends the least.