Thinking aloud test – loud and clear

The Thinking Aloud test is considered the number 1 usability tool by Jakob Nielsen, the principal of the Nielsen Norman Group, a leading voice in the user experience field. This kind of test offers many benefits but also some disadvantages. In this post, I will discuss what it is exactly, the Pros and Cons and what you need to perform one.


Photo by Christin Hume on Unsplash

What is Thinking Aloud Test?

A Thinking Aloud Test is an empirical testing method of interface design with representative users. Nielsen describes it as the most simple and valuable method of usability engineering. (Nielsen 2012) Originally adopted in psychological testing, this evaluation tool is being increasingly used in evaluative testing processes and interactive products.

Recruiting the rights participants is critical for your results to be valid. The participants of the test should represent your target group, in other words, your actual users. Think about expertise – are your users tech-savvy or do they tend to be relatively inexperienced with technology? What are their cultural backgrounds? Or education level?

The test consists of one task or a set of pre-defined tasks involving the website, system or application under test conditions and requests the test user to verbalize all procedures, ideas, logical linkages and opinions necessary for the completion of the required task or set of tasks.

Benefits and Disadvantages

There are a lot of advantages of performing a Thinking Aloud test. It is cheap, provides plenty of process data, eloquent quotes and it requires a small group of test users, from 3 to 5. Another positive point is the acquisition of indirect information on the satisfaction of the user through informal comments and facial expressions. It is also flexible, can be applied any stage in the development lifecycle and convincing, since feedback and insights coming straight from users are hard to ignore. However, this method also has some disadvantages. It can slow the users down, they might think more before acting and it cannot provide performance data. (Andrews 2013) The facilitator can sometimes change user behavior and act as a bias for the results.

How to perform one?

To perform a good Thinking Aloud test is it necessary to have some preparation such as a good environment, the appropriate equipment and, of course, test users that are compatible with the representative user profile from the object being tested, as mentioned before.

There are different roles to be played by the different members of the evaluation team. These are:

  • The test facilitator – the person who in general is in charge of the test, responsible for all interaction with test users.
  • The data logger – the person who records activities and events of interest on paper, including time of occurrence.
  • The video operator – the person responsible for recording the entire test proceedings, including initial instructions and debriefing.
  • The computer operator – the person who plays the role of the computer in a paper prototype, who resets the interface to a clean state for each new test user and who restarts after a system crash, unexpected hang-ups, etc.

Before doing the Thinking Aloud Test the users need to be prepared and trained to assure that they can execute the test. Demonstrate short videos of previous tests are a good way of doing that. Another nice way is to show how to proceed using an unrelated task or practice the technique using a different interface and unrelated task. Explain that questions may arise and be made during the process, but will not be answered until the end of the test. (Barnum 2010)


Although this type of test has some disadvantages, it is still a very good and cheap inspection method for usability testing, what it is great for stakeholders. It can determine users’ expectations and identify what aspects of a system are confusing. It can also easily detect vocabulary problems, what is especially important for content strategists. Now it is over to you! What do you think about it? Share your thoughts in the comment session.



(Nielsen 2012) Jakob Nielsen; Thinking Aloud: The #1 Usability Tool, 2012.

(Barnum 2010) Carol M. Barnum; Usability Testing Essentials; Morgan Kaufmann, 2010.

(Andrews 2013) Keith Andrews; Human-Computer Interaction: Lecture Notes; 15 Mar 2013.



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