CrossKeys: Text Entry for Virtual Reality Using a Single Controller via Wrist Rotation

Text entry has long been an indispensable part of people's lives; notwithstanding, in virtual reality (VR), an efficient and handy text entry method for such an environment is still wanted. There are two negative factors in the very majority of existing text entry methods: 1) constrained by two-dimensional mapping; 2) must manipulate with both hands to ensure efficiency. Few are employing the three-dimensional space a virtual environment provides, with which text entry could perform much better; also, even with several methods enabling one-hand manipulation, the trade-off is off-balance when sacrificing performance. Therefore, we propose an innovative text entry method to achieve a faster speed, higher accuracy, and better user experience. We design a cross-like layout to reduce the average distance of spatial displacement when selecting characters. In selecting and entering characters, a user simply rotates the wrist and points the embodied controller to one of the seven character blocks in the virtual environment; afterward, within the selected block, the user enters the target character or auto-completion candidate word via two basic trackpad interactions, touching and clicking. We evaluate our CrossKeys mainly based on two criteria: efficiency, task load, and three tasks: learnability and performance test, fatigue test, and evaluation of in-motion performance. To evaluate efficiency, we analyze words per minute (WPM) and error rate (NCER, TER); to evaluate task load, we analyze NASA-TLX and Simulator Sickness Questionnaire (SSQ) results. According to the data from our participants after only 2 hours of first-time training, our CrossKeys performs well with an average WPM of 17.73, a peak WPM of 24.73, and an error rate (NCER) of 0.30% along with a low task load.