Understanding freehand gestures: a study of freehand gestural interaction for immersive VR shopping applications

Unlike retail stores, in which the user is forced to be physically present and active during restricted opening hours, online shops may be more convenient, functional and efficient. However, traditional online shops often have a narrow bandwidth for product visualizations and interactive techniques and lack a compelling shopping context. In this paper, we report a study on eliciting user-defined gestures for shopping tasks in an immersive VR (virtual reality) environment. We made a methodological contribution by providing a varied practice for producing more usable freehand gestures than traditional elicitation studies. Using our method, we developed a gesture taxonomy and generated a user-defined gesture set. To validate the usability of the derived gesture set, we conducted a comparative study and answered questions related to the performance, error count, user preference and effort required from end-users to use freehand gestures compared with traditional immersive VR interaction techniques, such as the virtual handle controller and ray-casting techniques. Experimental results show that the freehand-gesture-based interaction technique was rated to be the best in terms of task load, user experience, and presence without the loss of performance (i.e., speed and error count). Based on our findings, we also developed several design guidelines for gestural interaction.