MaxDiff: Determining what Customers Value Most

MaxDiff: Determining what Customers Value Most

MaxDiff (Maximum Difference Scaling) is a statistical method created by Jordan Louviere in 1987. Survey respondents (e.g. potential clients) are shown a set of the possible items (preferences) and are asked to indicate the BEST and WORST items (or MOST and LEAST important / appealing. MaxDiff uses a set in which a respondent evaluates four items: A, B, C and D. If the respondent says that A is best and D is worst, these two responses inform us on five of six possible implied paired comparisons:
A > B, A > C, A > D, B > D, C > D
MaxDiff questionnaires are relatively easy for most respondents to understand. Furthermore, humans are better at judging items at extremes than in discriminating among items of middling importance or preference. MaxDiff is an antidote to standard rating scales or importance scales. Respondents find these ratings scales very easy but they do tend to deliver results which indicate that everything is "quite important", making the data not especially actionable. MaxDiff forces respondents to make choices between options, whilst still, at the end of the day delivering rankings showing the relative importance of the items being rated.