I am programming a CBC survey with 6 attributes (2-3 attribute levels each, ranging from least to preferred levels).
I have decided to chose the balanced overlap design strategy, mainly because of the fact that some respondents might have critical "must-have" levels. I find it attractive to show respondents with choice tasks where both concepts have the same most important, must-have level, so that I have a chance to observe how that respondent evaluates attributes beyond that first attribute level.
Now my question is: with my current design (two options, six attributes, balanced overlap), the two options that are shown in each choice task always contain a minimum of 1-3 attributes that are equal in terms of levels. However, the equal attribute levels are sometimes set at the least preferred level. In order to allow respondents to provide realistic answers and to observe attributes beyond the must-have levels, I would prefer that the "equal attribute levels" of the two concept options would be set at the most preferred and not least preferred levels.
My question is: is there a way to automatically program the CBC design in such a way to have those attribute levels where there is no difference between the two options set at the most preferred level?
If there is not automatic way to achieve this, I could manually alter the design of the choice task (by exporting the design, manually changing it, and then importing it again). Is there any reason why this should not be done?
Thanks a lot for helping me in this regard!