## 6 Experiments  
Following the development and the implementation presented in the previous sections, a series of tasks, involving the control of a computer mouse and keyboard, were designedto test the system in a real-life scenario. The hand gesture interface was compared against (and combined with) the AssystMouse [39], a head movement-based software, to control the mouse using a webcam. The first objective of the tests was to assess the performance of the hand gesture interface by first comparing it to the AssystMouse software. Then, the tests aimed to evaluate the usage of the hand gesture interface, when combined with the AssystMouse software. In this case, AssystMouse was used to control the mouse and the hand gestures, provided quick keyboard shortcuts (e.g., _Tap_ to copy and _tap-tap_ to paste). The experimental setup is presented in Figure 10. It includes an IMU to input gestures, a webcam required by the AssystMouse, and display monitors showing the graphical interface (displaying the modes, sequences, and options) and the actual workspace where the tasks were performed.  
The experiments have been performed by five healthy participants (2 male and 3 female) between 24 and 35 years old. In order to assess the performance of the hand gesture interface, they had to execute two tasks. To set up the experiment, each participant had to record his or her own gestures, then build sequences and map them to specific control modes of the mouse and keyboard. They first recorded three distinct hand gestures:  
1. _Tap_: a simple tap on the table.
2. _Swipe_: a swipe on or above the table.
3. _Shake_: wrist shake in the air.  
To do so, the participants had to execute each gesture ten times.  
The first task, shown in Figure 11, was to open a folder on the PC desktop, then open the spreadsheet in the folder and change the color of the yellow cell to red. This task required the participant to be precise with the mouse, as well as to execute single and double clicks. The participants had to complete this task using first the hand gesture interface and then the AssystMouse and they were timed for both interfaces. With the gestures, five sequences were created : _Tap_, _Tap-Swipe_, _Shake_, _Shake-Swipe_, and _Swipe_. Those sequences were mapped to the mouse modes left-click, up, down, left, and right. For this task, a button was used to activate the mode once in it. For instance, if the participant executed _Tap-Swipe_ to enter the mouse-up mode, they had to press the button to actually make the cursor go up. Before the experiment, the participants had ten minutes to familiarize themselves with each interface.  
Figure 10: Experimental setup for the hand gesture interface evaluation.  
The second task was performed in the spreadsheet. The participants first had to copy and paste a cell three times with the AssystMouse only. Then, they had to do the same thing but using both the AssystMouse and the hand gesture interface. The first three sequences were remapped to the modes click, copy, and paste. Thus, the gestures could be used as shortcuts and the mouse was still controlled with the AssystMouse. This aimed to evaluate the suitability of the hand gesture interface when used as a complement to other available AT control systems.  
After the tests, the participants were asked to answer a questionnaire (which contained questions adapted from the QUEAD [40]) and to leave their comments.