Good morning,
When I do not use the optimal plan platform:
- I make a plan with 3 categorical factors each with 3 levels + I add only the 3 main effects => 18 tests recommended
- I make a plan with 3 categorical factors, 2 factors with 3 levels and 1 factor with 4 levels + I only add the 3 main effects => 12 recommended trials.
Why are there fewer tests for the 2nd plane while there are more factor levels for one of the categorical factors?
Thanks in advance
