think aloud protocol – πρωτόκολλο “σκέπτομαι μεγαλοφώνως” (see also question-asking protocol)

a technique in user testing where users are asked to speak their thoughts as they perform a task.

While the focus in user testing is primarily on how effectively a user performs the required tasks (and not on how users believe they are performing), verbalizations are quite useful in understanding mistakes that are made and getting ideas for what the causes might be and how the interface could be improved to avoid those problems.