Thinking Aloud Test

A Thinking Aloud test is usually an integral part of the user experience. During such testing, users of a website or product are encouraged to think aloud when using individual features. These mostly unconscious expressions are registered and evaluated. Thinking Aloud tests are very popular because they can be implemented with little financial and logistical effort. In most cases, these tests are still in the beta stage of a software, website or product.


At the beginning of the 1980s, psychology dealt intensively with the complex inner processes that occur in humans when they perform a certain action. This marked the beginning of the age of cognitivism, which is intensively concerned with human thinking. A primary question of research in this area was how to gain access to the inner processes in a person's brain.

One of the proven methods for this was finally found in "Thinking Aloud". It is assumed that people will be able to provide accurate guidance on their actions if they talk about it loudly during trading. For example, respondents were asked to express their thoughts when solving puzzles or mathematical tasks.

However, this method was quickly criticized because many researchers thought that the data collected using the Thinking-Aloud method was too subjective to be able to verify or falsify hypotheses. Finally, with Ericsson and Simons, two researchers took up the topic with the work "Verbal report as data" in 1984, a kind of basic work. In this scientific paper you define three levels of verbalization of actions:

  • Level 1: simple rendering, e. g. by number sequences or enumerations
  • Level 2: Non-language skills are verbalized, e. g. with illustrations or photos
  • Level 3: Actions are justified

The researchers finally assigned the first two stages to short-term memory. Consequently, they are also relevant for tests, while level 3 verbalization is derived from long-term memory and is therefore subjective.

Another important step towards Thinking Aloud Testing in practice was Clayton Lewis' paper "Using the Thinking Aloud method in cognitive interface design", which he published in 1982 as an employee of IBM. He describes for the first time how the Thinking-Aloud method was used for testing. In the following years, many other publications on the same subject were published.

Today, Thinking Aloud tests are used by industry, advertisers and product developers alike. In contrast to Ericsson and Simons, the results of the tests are now starting at Level 3. Because it is usually precisely the clues that UX designers want to hear from their test persons.


In comparison to other methods such as eye tracking, a Thinking Aloud test does not require extensive technical equipment. For this reason, such a test procedure can be used relatively quickly.

First of all, special action scenarios are outlined which are expected from an average user when dealing with a product or website. The test users are then given tasks to perform. At the same time, you should say out loud what they think when using, what questions they have and what they don't understand. All statements are recorded and evaluated afterwards.

Jakob Nielsen, CEO of the group of the same name, reduces the process of a Thinking Aloud test to three steps:

  • “Recruit representative users.
  • Give them representative tasks to perform.
  • Shut up and let the users do the talking.”[1]

Use of the method[edit]

With the help of a Thinking Aloud test, advertisers and product developers can almost follow "live" how a potential customer interacts with a product. This is because the considerations for each individual action step, for each new web view or product function are provided directly and can be compared with the expected actions. In this way, software programs, websites or consumer products can be designed more precisely by not intuitively anticipating the actions of the customer, but rather by predicting them fairly accurately with the help of empirical tests. The larger the set of data analyzed in a Thinking Aloud test, the more likely the user's actions become.


Thinking Aloud tests have the following advantages:

  • Low-cost procedure: no experts are needed, and no expensive equipment has to be purchased
  • Only a few subjects are needed for relevant results
  • The clients receive spontaneous and authentic reactions from users
  • Misinterpretations can be virtually ruled out, as the test users have no possibility to revise their comments again.
  • Simple combination with other test procedures regarding user experience
  • Flexible applications

Possible disadvantages[edit]

  • The tests are never authentic application situations, but mostly artificial laboratory conditions
  • There are time delays in the application, because the users have to express their thoughts out loud
  • Small samples are often not sufficient for transferring to large quantities
  • Loud thinking can influence the actions of the test persons
  • The investigation of more complex action steps requires a lot of attention


  1. Thinking Aloud 1 Usability Tool Accessed on June 18, 2014