EYE TRACKING AND THINK-ALOUD PROTOCOLS AS COMPLEMENTARY USABILITY TESTING METHODS: EXPLORING INTERFACES DEMONSTRATING PHYSICAL PROCEDURES

Usability testing methods are important for understanding how users react to a user interface. However, such behavioral understanding of the user's task approach does not necessarily lead to an understanding of the users' thought process about a specific user interface or how a reader organizes his thinking that actually led to the behavior, as is often observed during testing sessions. A human-computer interaction-based approach and sometimes a usability approach remains satisfied with such behavioral outcomes for data collection without a follow-up inquest into the cognitive processes that are so important in exploring not only the outcome, but also the thought process that led to the outcome. Here lies the problem with the eye-tracking method. While the eye-tracking method might help with one-on-one mapping between eye fixation patterns and actual on-screen activities, it will not help in understanding the cognitive processes that led to the resultant actions observed. This article suggests that concurrent and retrospective think-aloud protocols, if designed properly with leading, concrete, specific, and sequential questions to help explore a procedure, might help in the understanding of cognitive processes that led to observed behaviors. Capturing a reader's exact thought process becomes more complex with physical procedures. This article strongly advocates that think-aloud protocols and eye-tracking methods should complement each other in a logical way; therefore, presenting concrete examples of physical procedures and explains and provides recommendations as to how think-aloud protocols might complement eye-tracking methods.