International Statistical Review

Traditional and choice‐based conjoint analyses (CAs) have used full or fractional factorial designs to generate concept profile descriptions. However, these designs confound two factors when costs are associated with attributes: first is the total cost of the concept profile, and second is the allocation of costs among the attributes. Both factors may influence consumers' preferences. So far, these issues have not been separated in the CA literature. The present paper shows how mixture–amount designs used in industrial experiments may be used to separate amount and mixture effects in traditional CA. The extension to choice‐based CA using balance incomplete block (BIB) designs is also given.