MaxDiff scaling is a method for obtaining preference or importance scores for multiple items like brand preferences or product features. It involves respondents choosing the most and least important items from sets, allowing direct trade-offs. This provides ratio-level data that is easy to interpret on a common 0-100 scale. The method has advantages over rating scales in discriminating between items and avoiding scale bias. Case studies demonstrated its use for testing feature benefits and preferences for a technology company's product line extension.

1. MaxDiff ScalingA Better Way to Understand Preference / ImportanceNico Peruzzi, PhDhttp://twitter.com/NicoPeruzziPhD 408-202-1521nperuzzi@orconsulting.comOctober 2010

2. AgendaCopyright 2010 Outsource Research Consulting | All Rights ReservedWhat is MaxDiff?Why use it?Why is it better than rating scales?How is it different than conjoint?Case studies

3. What is MaxDiff?MaxDiff (Maximum Difference Scaling) is an approach for obtaining preference/importance scores for multiple items:Brand preferencesBrand imagesProduct/service featuresMessagesAdvertising claimsBenefitsMaxDiff is also known as “best-worst scaling”Copyright 2010 Outsource Research Consulting | All Rights Reserved

4. How many times have you tried to interpret the difference between a mean of 4.2 and 4.4 on a 5-point rating scale? You know the futility of that exercise.Copyright 2010 Outsource Research Consulting | All Rights Reserved

5. Types of DataNominal – categories (gender, political affiliation, etc.)Ordinal – rankings (college football ranking, survey rankings, etc.), Likert scalesInterval – Temperature Fahrenheit, Likert scales often treated as if they were intervalRatio – height, weight, temperature Kelvin, MaxDiff Scores!Copyright 2010 Outsource Research Consulting | All Rights Reserved

6. MaxDiff DesignCopyright 2010 Outsource Research Consulting | All Rights ReservedCard #1Card #2Card #3Experimental Design/ RandomizationCard #4Card #5Card #6Card #7Etc.

7. Research has shown that MaxDiff scores demonstrate greater discrimination among items and between respondents on the items. Respondents see a number of screens like this one. Each time, they simply choose the most important (or preferred) and least important item

8. No scale bias or different interpretation across respondents or languages/cultures/education levels

9. Any downside? TimeCopyright 2010 Outsource Research Consulting | All Rights Reserved

10. Easy to InterpretMaxDiff scores are easy to interpret. They are commonly placed on a 0 to 100 common scale and sum to 100. Thus, when you see a “10” it has twice as much value as a “5”You can’t do this with rating scale resultsCopyright 2010 Outsource Research Consulting | All Rights Reserved

11. Why not use conjoint?MaxDiff is related to conjoint in that it forces trade-offs, however…Conjoint is only appropriate when you want to estimate how multiple attributes taken together affect overall preferenceMaxDiff looks at a lot of “items” (levels) within a single attribute (variable) (e.g., product features)…Whereas conjoint looks at multiple attributes, each with some number of levels; conjoint commonly examines the feature-price mixCopyright 2010 Outsource Research Consulting | All Rights Reserved

12. Case StudiesCopyright 2010 Outsource Research Consulting | All Rights Reserved

13. Case Study: Feature BenefitsClient: Data Robotics, Inc.Objective: Testing benefitsMethod: MaxDiff with 7 itemsCopyright 2010 Outsource Research Consulting | All Rights Reserved

14. 12Data Robotics Vision and MissionGive creative professionals, prosumer, and SMB customers the best storage experience ever

15. BeyondRAID

16. Easy: Self-managing storage arrays that eliminate the difficult and confining choices associated with RAID

17. Affordable: Best in value upfront and over time − savings compound with “pay-as-you-grow” storage

18. Safe: Products offer single and dual drive redundancy with self-healing capabilities

19. Expandable: Instantly increase capacity by inserting a new hard drive or replacing the smallest drive – even when all hard drive bays are full12

20. Drobo Product FamilySiSCSI SANDirect Attached Storage - DASNetwork File SharingFS

21. What are some benefits of Drobo? Which statements most resonate with buyersI am constantly running out of storage. I need to instantly expand and grow my capacity without downtime or delay. I find RAID too complex and want something easier to manage. I like the ability to buy drives when I need storage, instead buying storage ahead of my needs.I need a storage device that consolidates my needs on a single, easy to use array rather than multiple devices that require individual administration and create unnecessary clutter. I want a storage device that can manage itself so that I don’t need to use consultants or hire dedicated staffing to manage it. My data is extremely valuable - I need a system that protects me from drive failures. The ability to mix and match hard drives of different capacities, from any drive maker is important to me. Copyright 2010 Outsource Research Consulting | All Rights Reserved

22. Results100 point ratio scaleItem 1 is 24% more preferred than Item 2, and 89% more preferred than Item 3Copyright 2010 Outsource Research Consulting | All Rights Reserved