An Examination of the Use of Unacceptable Levels in Conjoint Analysis.

Unacceptable levels in conjoint analysis are studied using both a full profile method and Sawtooth Software's Adaptive Conjoint Analysis. The utility of an unacceptable level was set equal to a value that would have been assigned if the unacceptable levels question was not asked, but the respondent treated that level as unacceptable. With ADA, this resulted in a model with (a) superior predictive power relative to a model that eliminates alternatives with unacceptable levels and (b) equivalent predictive power to a compensatory model that does not consider unacceptable levels. Furthermore, in this application, this was accomplished even though the respondent was presented with approximately 30 percent fewer paired comparison observations. Copyright 1992 by the University of Chicago.