Abstract

Haptics has been used as a natural way for humans to communicate with computers in collaborative virtual environments. Human-computer collaboration is typically achieved by sharing control of the task between a human and a computer operator. An important research challenge in the field addresses the need to realize intention recognition and response, which involves a decision making process between the partners. In an earlier study, we implemented a dynamic role exchange mechanism, which realizes decision making by means of trading the parties' control levels on the task. This mechanism proved to show promise of a more intuitive and comfortable communication. Here, we extend our earlier work to further investigate the utility of a role exchange mechanism in dynamic collaboration tasks. An experiment with 30 participants was conducted to compare the utility of a role exchange mechanism with that of a shared control scheme where the human and the computer share control equally at all times. A no guidance condition is considered as a base case to present the benefits of these two guidance schemes more clearly. Our experiment show that the role exchange scheme maximizes the efficiency of the user, which is the ratio of the work done by the user within the task to the energy spent by her. Furthermore, we explored the added benefits of explicitly displaying the control state by embedding visual and vibrotactile sensory cues on top of the role exchange scheme. We observed that such cues decrease performance slightly, probably because they introduce an extra cognitive load, yet they improve the users' sense of collaboration and interaction with the computer. These cues also create a stronger sense of trust for the user towards her partner's control over the task.