Using the Think Aloud Protocol in an Immersive Virtual Reality Evaluation of a Virtual Twin

Employing virtual prototypes and immersive Virtual Reality (VR) in usability evaluation can save time and speed up the iteration process during the design process. However, it is still unclear whether we can use conventional usability evaluation methods in VR and obtain results comparable to performing the evaluation on a physical prototype. Hence, we conducted a user study with 24 participants, where we compared the results obtained by using the Think Aloud Protocol to inspect an everyday product and its virtual twin. Results show that more than 60% of the reported usability problems were shared by both the physical and virtual prototype, and the in-depth qualitative analysis further highlights the potential of immersive VR evaluations. We report on the lessons we learned for designing and implementing virtual prototypes in immersive VR evaluations.