LAUSR

To explore the human–machine interaction and working efficiency of smartphone games, this study surveyed the relationship between the virtual keys in smartphone games and the controllable operating range of both thumbs, using a mobile fighting game as the experimental stimulus. This study analyzed users’ preference for virtual keys to characterize smartphone gaming interactions that employed both thumbs. For all subjects, operating characteristics and the placement distribution of both thumbs were recorded. In addition, their operating preferences were evaluated using principal component factor analysis. The 10 element dimensions were reduced to 4 factors: key feedback degree, key usability, relative key position, and relative key size. The study results provide a reference for human–computer interface designers and contribute to the literature on games.