\section{Training and Feedback}\label{training}

One way of providing a better understanding of the system is through adequate training. In the tests conducted, the users spent only few minutes test-driving the wheelchair, which has proven to be insufficient. This re-iterates the benefits of training environments such as the VR wheelchair simulator developed at the University of Strathclyde.

Feedback given to the user to indicate the reason for shared control behaviours would minimise unpredictability of the wheelchair movements. It can be quite beneficial in a training environment where users can learn to develop driving skills that make use of shared control effectively so as to minimise workload, while at the same time providing sufficient challenges. Previous studies conducted at the University of Strathclyde using human-in-the-loop design of BCI-controlled wheelchair operation has demonstrated the positive effects of appropriate feedback on user performance (Grychtol et al, 2010). A three-dimensional arrow displayed on the simulator screen was developed for this research to act as a cue. The use of this arrow can be adopted for the purpose of providing feedback in shared control operation of the wheelchair. The user could possibly be suggested the direction to take, for instance to navigate through a narrow passage when Collision Avoidance assistance is activated. Alternatively, in the same scenario, the arrow can be used to indicate the prohibited directions set by the Collision Avoidance mode, thus enabling the driver to use his or her decision-making abilities to tackle the situation.
