# StreamflowVL: A Virtual Fieldwork Laboratory that
## 5 Preliminary Testing Procedure

Table 1: Final questionnaire on students’ satisfaction. through high quality images (\(\mu\) = 4.00, \(\sigma\) = 0.74) and the clear visualisation of different objects (\(\mu\) = 4.20, \(\sigma\) = 0.89), allowing simple interpretation of texts and numerical data (\(\mu\) = 4.13, \(\sigma\) = 0.90). They also made comments and suggested ways to further improve the realism and immersivity of the VR application through:  
* Increasing the light refraction, the free surface waves, and the water transparency in depth (Figure 4). * Modifying the colours of some objects. * Fading the bright intensity in the distance. * Adding sound effects such as the water flowing along the channel, the rustle of leaves, and the chirp of birds. With regard to the technical features of the VL, the students were able to quickly move around in the virtual scene (\(\mu\) = 4.07, \(\sigma\) = 0.87) and manage the finger gestures to activate various features (\(\mu\) = 3.97, \(\sigma\) = 0.93). However, the first students showed some problems with grabbing the equipment and placing it correctly, especially in hammering the posts in and accurately using the velocity sensors. To remove the first problem, the technician enabled each object to be highlighted in yellow at the user's touch (Figure 5). To simulate the correct use of the instruments, a control light was inserted on each of them. Therefore, when the operator starts the simulation by interacting with an instrument, its control \begin{table}
\begin{tabular}{l l c c} \hline \hline
**No** & **Question** & \(\mu\) & \(\sigma\) \\ \hline
1.1 & The 3D VR scenes accurately reproduce the real fluvial environment & 4.23 & 0.82 \\
1.2 & VRLab displays the real objects in a clear way & 4.00 & 0.74 \\
1.3 & The texts and the numerical data from the VRLab are well readable & 4.20 & 0.89 \\
1.4 & The images from the VRLab are of good quality & 4.13 & 0.90 \\ \hline
2.1 & VRLab allows quickly moving across the scene & 4.07 & 0.87 \\
2.2 & VRLab allows fast managing the fingers gesture to activate various features & 3.97 & 0.93 \\
2.3 & VRLab allows quickly grabbing and handling the equipment & 3.87 & 1.04 \\ \hline
3.1 & VRLab supports the correctly placement and use of the equipment & 4.27 & 0.91 \\
3.2 & VRLab provides appropriate and accurate guidance messages & 4.67 & 0.61 \\
3.3 & VRLab facilitates the simultaneously execution of different actions & 3.77 & 0.94 \\
3.4 & The visualisation of video tutorials enhances the knowledge of the measuring techniques & 3.90 & 0.80 \\ \hline
4.1 & VRLab is complement to the teacher explanation during the theoretical classes & 3.63 & 1.27 \\
4.2 & The use of virtual resources is a more effective methodology than traditional learning methods & 3.80 & 1.13 \\
4.3 & VRLab trains on the methods and techniques for an accurate measurement procedure & 3.97 & 1.03 \\
4.4 & VRLab trains to think more critically and better understand some fluvial processes & 4.37 & 0.81 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Values of mean, \(\mu\),and standard deviation, \(\sigma\), based on the scores obtained from the questionnaire. Figure 4: 3D VR scene of the fluvial reach (**a**) without and (**b**) with the light refraction and the water transparency in depth. light is red until the instrument is placed in the desired position; when the correct position is achieved, the control light turns green in order to generate user feedback on the correct execution of the task. For example, while marking the site along the banks, the user will keep hitting the top of the post with the hammer until the green light is displayed (Figure 6). These improvements introduced in the VRLab increased the rating of question 3 in category 2 and question 1 in category 3 (\(\mu\) = 3.87, \(\sigma\) = 1.04; \(\mu\) = 4.27, \(\sigma\) = 0.91). Another technical problem observed during the simulated measurement procedure was the abandonment of the instruments and their fall into the water, see Figure 7a, which increased the time of the students' virtual experience.