How would you like to treat the case where the respondent narrows the acceptable levels of a feature to only one (all other feature levels are totally unacceptable)? Your choice may influence the respondent's relative importance score of each feature. Relative feature importance is measured as the value gained by moving from the least preferred level to the most preferred level for that feature...
Do you want to...
Combine the most preferred feature level with the next lowest level. (default) If there is no lower level, then the next highest level will be selected. (Use when there is a linear or curvilinear order effect in the feature levels i.e., more or less is worse)
Combine the most preferred feature level with a random feature level. (Use when there is no order among the feature levels)
3. Present / Absent
Combine the most preferred feature level with a "No $InsertFeatureLevelName". (Use when this is an all or none feature)