Example of specifying generatorsmain topic interpreting results session command see also
Example of specifying generatorsSuppose you want to add two factors to a base design with three factors and eight runs.
1 Choose Stat > DOE > Factorial > Create Factorial Design.
2 Choose 2-level factorial (specify generators).
3 From Number of factors, choose 3.
4 Click Designs.
5 In the Designs box at the top, highlight the row for a full factorial. This design will serve as the base design.
6 Click Generators. In Add factors to the base design by listing their generators, enter D = AB E = AC. Click OK in each dialog box.
Session window output
Fractional Factorial Design
Factors: 5 Base Design: 3, 8 Resolution: III Runs: 8 Replicates: 1 Fraction: 1/4 Blocks: 1 Center pts (total): 0
* NOTE * Some main effects are confounded with two-way interactions.
Design Generators: D = AB, E = AC
Alias Structure (up to order 3)
I + ABD + ACE
A + BD + CE B + AD + CDE C + AE + BDE D + AB + BCE E + AC + BCD BC + DE + ABE + ACD BE + CD + ABC + ADE |
The base design has three factors labeled A, B, and C. Then Minitab adds factors D and E. Because of the generators selected, D is confounded with the AB interaction and E is confounded with the AC interaction. This gives a 2(5-2) or resolution III design. Look at the alias structure to see how the other effects are confounded.