Colleagues, can't wrap my mind on simple question, please help!
I have two products and list of their attributes. My respondents make an answer which product on each attribute they prefer. Finally they choose which product they are preferred overall.
This is an example of an answer from a single respondent:
Product_A Product_B No_Preference Attr 1 1 0 0 Attr 2 1 0 0 ... Attr 20 0 0 0 Final_Choice 1 0 1
There are two goals:
1) to learn the final choice drivers, which attributes impacts more on the final choice
2) Is there difference between drivers between two products. Example: Imagine, Product_A has great color, and Product_B has great scent. All the rest attribs are very similar. I want to detect that scent and color are drivers that differ significantly and all the rest do not.
The problem is that that Product_A is 25% more popular (on the final choice) and people tended to choose its attributes even more often (every preferred Product_A has on average 20% more preferred attributes than Product_B).
I tried to apply 2-samples Z-test of proportions and Chi-squared test on every attribute but both yield significance on every attribute since the proportions are rather different. It gives me no information. It seems I need to compare kind of relative impact (meaning I have to somehow exclude different "popularity" of the products and different level of their attributes' "attractiveness" per product)
I also tried logistic regression but it does not work either: people tended to prefer attributes of the product that they are finally chosen, so logistic gives me just perfect fit.
The problem seems logically similar to McNemar test but since every respondent was able to make only one choice (per attribute) I can't apply this test too.
What have I missed?