Hello everyone! I am trying to do a fractional factorial design for a choice experiment, with one constraint. Is anyone aware on how to do it? I have three factors, 2 with 3 levels and 1 with 2 levels: L1: A B and C; L2: F D and J; L3: Black and Red. When the last is Red, it does only combine with D, but not with F or with J, though it does with A B & C. Can anyone help?
