choice-metrics.com

Hello,

I would like to do a labeled choice design (first time for me) and I have 5 different alternatives (5 different type of bread which vary based on price) plus the no buy option. I believe that normally one would have the 5 alternatives plus the no buy option in one choice set. However, I would like to have choice sets with only 2 alternatives (like for unlabeled design) plus the no buy option. Is this possible such type of design or I am totally wrong?

Thank you vary much in advance.
D.

Yes this is possible. There are two options.

(1) Include the type of bread as a dummy coded attribute in the utility functions of BreadA and BreadB. Instead of BreadA and BreadB, you can show the type of bread as the label on top. The coefficients of the dummy coded attribute replace the alternative-specific constants. Of course you can also add the opt-out. This is the easiest option, especially if all other attributes and coefficients are generic. If the attribute/coefficients are alternative-specific, you would need to make interactions with the type of bread dummies.

(2) Create a partial choice set design where you specify 5 bread types as alternatives (plus opt-out) but systematically only show 2 bread types in the choice set. This can be achieved by making a special candidate set and using the modified Federov algorithm, see the Ngene manual.

Michiel