I just completed a CBC where we tested something like a lunch plate where there could be 4 attributes of food categories, such as meat, vegetables, rice, etc. Each food category also had a "null" (i.e., no meat) option. I set it up so that there always had to be 2 or 3 foods NOT null.
Now I just got the data back and tried to analyze it another way. I exported the design to Excel and created a new attribute of whether the dish had 2 or 3 food categories in it to explicitly quantify having 2 vs. 3 not being null. But when I test that design, it says it is deficient. That makes sense, because it's completely dependent on the other attributes.
So is there some way to recode the design file to explicitly analyze the number of null levels?