Method 19 of 100: Laddering Questions

100 User Experience (UX) Design and Evaluation Methods for Your Toolkit

by Chauncey Wilson

This is the 19th in a series of 100 short articles about UX design and evaluation methods. Today, the focus will be on the laddering question method, a semi-structured interview technique where you ask “why, how, what, and ‘tell me more’” questions multiple times to drill down, up and sideways to go from general to specific, specific to general, or from one item in a category to another item.

Method 19 of 100

Laddering questions can provide insight into attitudes, beliefs, and values that affect requirements, brand image, consumer preferences, and buying decisions. For example, you might be interviewing someone as she works with software in her office. During the interview, the person says, “This feature is great!” Then you would follow up with a “ladder down” question – “Why is that feature great?” The person might say “It saves me a lot of time.” Then you continue with another ladder-down question – “Why does it save you a lot of time?” The person replies that “I didn’t have to find the dialog box – I could just use the pop-up menu.” You could go further, but in this series of “why” questions, you have gone from a general emotional statement to one that gets at the underlying issue – a particular feature reduces the amount of movement and search time required to perform a task. Laddering is a way to move from surface statements to root causes, details that are actionable, or core values that might affect adoption or satisfaction or loyalty.

In addition to drilling down, you can also drill sideways and ask a set of questions that reveal multiple examples or categories related to a particular topic. For example, if you were interviewing a usability expert about what methods he uses to discover usability problems, he might say “usability testing.” You could then ask “Are there any other methods that you use to get at usability problems?” He would pause and say “pluralistic reviews.” You could drill down on “pluralistic reviews” and then drill sideways and ask for other methods that involve users, getting the answer “diary studies.” A combination of drill-down and drill-sideways questions can provide useful and persuasive data.

There are a number of methods that are based on laddering questions including the “5-Whys” method that is often associated with root cause analysis.   

When to Use:

You can use laddering questions to:

• Understand organizational culture
• Complement other methods
• Elicit and understand knowledge from experts
• Elicit knowledge and details about a new domain
• Determine details about how new features and product attributes affect the user experience
• Produce data that are actionable
• Link features and product attributes with user/customer values

Strengths and Weaknesses:

+ Laddering is a technique that gets at core values and the underlying reasons for particular behaviors or choices.

+ Laddering is a way to elicit semi-tacit information that might not be revealed by other UX methods.

- Laddering can be tiring for participants who are continually asked “why” or other laddering questions.

- Conducting interviews with many laddering questions requires a facilitator who can keep the participant engaged. People who use laddering questions need to be comfortable with the repetitive questioning style and be prepared to vary their prompts as needed.

- On some occasions, laddering can get into sensitive issues (e.g., how corporate politics affects productivity).

- Laddering questions assume that there is hierarchical information. In some domains, the information may not be represented hierarchically.

Procedure:

You can conduct interviews that are focused on laddering or you can use laddering questions as part of a more general interview protocol. Here is a high-level set of steps for using laddering questions.

1. Develop a small set of laddering probes that you can use in your study. Consider problems for moving down, up, and sideways. Here are some ideas for laddering questions:
   
   “Why do you think that this product is “great”?  (laddering down when a person makes a general statement and you want to get an underlying value, attitude, principle or rationale)
   
   “Why is this important to you?” (laddering up when a person mentions a specific feature and you want to understand the higher level value of the feature)
   
   “Can you tell me about similar/different types of….?” (laddering sideways to get examples or variations)
   
   
2. During an interview, you can elicit features, attributes, concepts, or constructs of interest. You could, for example, ask a person to list the features that she disliked the most or that are most important to productivity.
3. Ask the person to prioritize the list and then begin doing a “laddering interview” starting with the items at the top of the list. The person might tell you that she most dislikes the collaboration aspects of the product. You could then ask “Why do you dislike the collaboration aspects?”
4. Ask laddering questions until you get answers that have reached “the end of the ladder” or that are actionable.
5. Repeat the laddering exercise with the next item in the list or the next item in the interview where laddering is useful.

References:

Corbridge, C., Rugg, G., Major, N.P., Shadbolt, N.R. & Burton, A.M. (1994)
Laddering: Technique and Tool Use in Knowledge Acquisition.
Knowledge Acquisition, 6, pp. 315-341

Hawley, M. (2009). Laddering: A research interview technique for uncovering core values. UXmatters. Retrieved on January 20, 2012 from http://www.uxmatters.com/mt/archives/2009/07/laddering-a-research-interview-technique-for-uncovering-core-values.php

Rugg, G., Eva, M., Mahmood, A., Rehman, N., Andrews, S. & Davies, S. (2002)
Eliciting information about organisational culture via laddering. Information Systems Journal, 12, pp. 215-229

Sherlock, G. & Rugg, G. Using laddering and on-line self-report to elicit design rationale for software Proceedings of EASE & PPIG joint conference, Keele University, 8-10 April 2003 Addendum, pp. 453-472

The ‘5-Whys’ Method. http://www.mapwright.com.au/newsletter/fivewhys.pdf

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What’s Next in the Series?

In the next post, I’ll describe the method of “Magic Things.”