Investigation of Indirect Oral Operation Method for Think Aloud Usability Testing

摘要

Usability testing with prototypes is typically conducted with a concurrent think-aloud protocol. Due to the simultaneous process of prototype operation and verbalization, participants of the think-aloud testing sometimes say very little and are likely to become silent when they are required to think abstractly or complete complex tasks. In this paper, we propose a method of user operation with oral instruction, which facilitates thinking aloud because oral operation would help participants to keep a continuous flow of verbalization. To investigate the quantity and quality of utterances made during think aloud protocols, we conducted a comparative study between oral and conventional manual operation methods. The study was carried out with two test objects: an interactive prototype of a touch-screen digital camera and photo album software with standard mouse/keyboard user interface. Our results demonstrated that the oral operation method was more effective in drawing more utterances for explanation and observation that would be an important source of discovering usability problems although the effect was dependent on the user interface of test objects.