Thinking aloud:

Jakob Nielsen's Alertbox, January 16, 2012 Thinking Aloud: The #1 Usability Tool Summary: Simple usability tests where users think out loud are cheap, robust, flexible, and easy to learn. Thinking aloud should be the first tool in your UX toolbox, even though it entails some risks and doesn't solve all problems. "Thinking aloud may be the single most valuable usability engineering method." Iwrote this in my 1993 book, Usability Engineering, and I stand by this assessment today. The fact that the same method has remained #1 for 19 years is a good indication of the longevity of usability methods. Usability guidelines live for a long time; usability methods live even longer. Human behavior changes much more slowly than the technology we all find so fascinating, and the best approaches tostudying this behavior hardly change at all. Defining Thinking Aloud Testing To define thinking aloud, I'll paraphrase what I said 19 years ago: Definition: In a thinking aloud test, you ask test participants to use the system while continuously thinking out loud — that is, simply verbalizing their thoughts as they move through the user interface. ("Simply" ought to be in quotes, because it's notthat simple for most people to keep up a running monologue. The test facilitator typically has to prompt users to keep them talking.) To run a basic thinking aloud usability study, you need to do only 3 things: 1. Recruit representative users. 2. Give them representative tasks to perform. 3. Shut up and let the users do the talking. Think-Aloud Benefits The method has a host of advantages. Mostimportant, it serves as a window on the soul, letting you discover what users really think about your design. In particular, you hear their misconceptions, which usually turn into actionable redesign recommendations: when users misinterpret design elements, you need to change them. Even better, you usually learn why users guess wrong about some parts of the UI and why they find others easy to use. Thethinking aloud method also offers the benefits of being: Cheap. No special equipment is needed; you simply sit next to a user and take notes as he or she talks. It takes about a day to collect data from a handful of users, which is all that's needed for the most important insights. Robust. Most people are poor facilitators and don't run the study exactly according to the proper methodology. But,unless you blatantly bias users by putting words into their mouths, you'll still get reasonably good findings, even from a poorly run study. In contrast, quantitative (statistical) usability studies are ripe with methodology problems and the smallest mistake can doom a study and make the findings directly misleading. Quant studies are also much more expensive. Flexible. You can use the method atany stage in the development lifecycle, from early paper prototypes to fully implemented, running systems. Thinking aloud is particularly suited for Agile projects. You can use this method to

evaluate any type of user interface with any form of technology (although it's a bit tricky to use thinking aloud with speech interfaces — see report on How to Conduct Usability Evaluations forAccessibility for advice on testing with blind or low-vision users who rely on screen readers such as JAWS). Websites, software applications, intranets, consumer products, enterprise software, mobile design: doesn't matter — thinking aloud addresses them all, because we rely on the users doing the thinking. Convincing. The most hard-boiled developers, arrogant designers, and tight-fisted executives usuallysoften up when they get direct exposure to how customers think about their work. Getting the rest of your team (and management) to sit in on a few thinking-aloud sessions doesn't take a lot of their time and is the best way to motivate them to pay attention to usability. (For more on how to motivate teams to deliver superior user experiences, see the course on Selling Usability: Convincing...