What Is a Think Aloud Protocol?

A think aloud protocol (TAP) is a testing method where subjects are asked to talk while they interact with a manual, device, or concept. They can discuss how they feel while working, and puzzle out problems and solutions aloud as they proceed. Many facilities record the testing, and observers also take notes. This information can provide important feedback to improve a product, understand how people use critical thinking to solve problems, and collect more general information about how people think and behave.

In this process, the tester sets up the environment, usually with minimal distractions to control for variables. The test subject may be given a task like using a manual to assemble something or troubleshoot a program. Subjects can also interact with unknown objects, or test things like computer software and mechanical controls for devices. The researcher tells the subject about the purpose of the test, typically stressing that the goal is to collect information as naturally as possible.

The tester in the think aloud protocol begins interacting with the subject of the test, offering thoughts. These might range from the dislike of a manual's layout to an attempt to fix a problem. A participant might, for example, be presented with a computer and asked to perform a task. The user can talk about trying to find the right program for the task, learning the controls of the program, and seeking assistance from the computer's documentation.

This approach requires a neutral observer who does not comment or interact during the think aloud protocol. If mistakes occur, the tester takes note of the conditions. Users testing a new cell phone, for example, might all make similar mistakes, suggesting that something is wrong with the interface; a button that the designers think is intuitive, for example, might be confusing. Likewise, the documentation in a manual to set up a desk could be missing a key piece of information that results in a consistent error during testing.

Scientific researchers can use the think aloud protocol to learn more about human cognition, not necessarily with the goal of testing a product or set of documentation. Increasing understanding of how people solve problems and approach new environments can help researchers with tasks like treatment of patients with cognitive deficits or the development of programs for people with learning disabilities. Dyslexic subjects, for example, might show through a think aloud protocol that an education program supposedly designed for them doesn't work as intended.