Should you include the “None of the above” option?
For your conjoint experiment, you can choose one of three options that characterise your product. This will affect how the “None of the above” option is presented to respondents and how analytics is run on the data we collect.
Why do these options depend on product types?
Consumers tend to think twice when it comes to buying new products. Therefore the chance of not buying any product in new categories is higher. This needs to be reflected in conjoint analysis as well.
The table below shows the percentage of “none of the above” responses for a sample of 709 experiments with two-stage response and 4863 experiments with the standard “none of the above” option (including both generic and brand-specific conjoint studies). It is split by type of response and by country (listing only top 12 countries of respondents):