I draw on your CCEA software to perform a consensus clustering on part-worth utilities (zero-centered-diffs). So far, I just included the part-worths for the attributes and refrained from taking the utility values of the dual-none option into account.
For my understanding, the utility of the dual-none tells me the threshold value when answering the question whether the respondent buys a product or not. Hence, only if the sum of the individual utilities from the product attributes exceed the utility of the dual-none, the respondent will purchase the product under consideration.
As a consequence, I have no idea how to include the dual-none into the clustering since the utility values differ dramatically. For example, respondent A has a utility for the dual-none of 10.1 while respondent B has 0.4 and respondent C -3.7. Compared to the part-worths of the attributes, it seems that the dual-none has a different scale. Therefore, I have the feeling of comparing apples and pears. Is this correct?
However, since I want to calculate relative attribute importances for the obtained groups afterwards, I stick to the hint in your CCEA manual and do not perform a standardization. Is there any possibility to include the dual-none in the clustering without standardization or is it ok to include it with the current scale?
Many thanks to all of you