## 5 Discussion  
Both developed prototypes of the application were used to examine the possibility of DGA support by the use of different forms of AR technology. In order to conduct the research, after testing of the applications in laboratory conditions, DG operators from one of the Polish airports were asked to test applications in conditions similar to operational ones. After 2 weeks of testing, they anonymously answered a few questions about their feelings and experiences. They were to evaluate the influence which--in their opinion--a given function could have on the reliability and the execution time of the DGA process. They had five grades (in accordance with the Likert scale) to assess the influence, where 1 means a strongly negative influence on operation execution, 3 means a neutral influence/the lack of influence and 5 means a strongly positive impact (the function is highly supportive). The asked questions are presented in Table 3 and results of the survey (average grades) are presented in the same table as well as in Figure 8. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{Smartphone Application} & \multicolumn{2}{c}{AR Goggles} \\ \hline Evaluate the influence on the DGA process on a 1–5 scale, where: & & & & \\
1 means negative influence (the function will decrease the reliability of a & & & & \\ supported operation in DGA or increase its duration), & & Reliability & Time & Reliability & Time \\
3 is neutral and & & & & \\
5 means positive influence (the function will increase the reliability of a & & & & \\ supported operation in DGA or reduce its duration): & & & & \\ \hline Presentation of detailed shipment data & 4.6 & 4.2 & 5 & 4.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The results of the assessment of applications supporting the DGA process. Figure 7: Results obtained while testing automatic recognition of DG labels. In Figure 8, one can see that the general assessment of both applications using AR technology could be summarized as positive. Most columns in the figure are significantly higher than the red line representing the neutral influence of the supporting function on the process. It means that their potential is positively evaluated by operators. The highest values can be observed for the presentation of detailed data of a shipment, the presentation of the law regulations and the automatic choice of an acceptance list. They are expected to increase the process reliability and reduce the process duration, especially in cases of the following:  
1. The reliability and duration when presenting law regulations (grades from 4.6 to 5.0);
2. The reliability when presenting detailed shipment data (grades from 4.6 to 5.0);
3. The reliability and process time when an acceptance checklist is automatically chosen in the form of smartphone function (grade 5). The red horizontal line in Figure 8 reflects the neutral influence on the reliability and the duration of DGA operations. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{2}{c}{Presentation of law regulations} & 4.6 & 5 & 4.8 & 5 \\ \hline Automatic comparison of shipment parameters with acceptable limits & 4.8 & 4 & 5 & 4.2 \\ \hline Automatic choice, presentation and fulfilling the acceptance list in an & 5 & 5 & 4 & 3.2 \\ electronic form & 3.2 & 4.2 & 3.8 & 4.8 \\ \hline Automatic verification of the text marking & 4.4 & 5 & 4.4 & 4.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: _Cont._  
Figure 8: The evaluation of the expected influence of tested applications using AR technology on the DGA process. It is worth to noting that the electronic filling out of an acceptance list is evaluated as more effective in the smartphone application while it is considered as less efficient when using of AR goggles. After discussions with operators, it has been revealed that this is because precise \"clicking\" (checking list boxes) in the virtual space is more difficult than clicking in a smartphone screen.