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Common Scale Hybrid Discrete Choice Analysis: Fusing Best-Worst Case 2 and 3 (2013)

The author (Orme) describes a hybrid discrete choice method that results in conjoint utilities on a common utility scale (where comparisons across levels of different attributes are supported). For certain research situations and when working with certain types of clients, there are valuable benefits to having commonly-scaled conjoint utilities. The key to obtaining the common utility scale is to employ both MaxDiff and CBC-type questions within the same questionnaire.

Although MaxDiff and CBC utilities are shown to not be equivalent, they tend to be very similar (correlation of about 0.90 or higher). Evidence is presented that MaxDiff scores can perform almost at the same level as CBC utilities in terms of predicting CBC-formatted holdout tasks. Orme suggests that if the goal is to predict CBC-looking holdouts (or real-world purchase decisions), the CBC tasks alone could be used to develop a market simulator. Not surprisingly, fusing MaxDiff and CBC slightly degrades predictions of CBC-formatted holdout tasks. If the goal is to present and interpret part-worth utilities on a common scale, while leveraging the strength of the conjoint approach to preference elicitation, then the fusion of MaxDiff and CBC tasks certainly has benefits.

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