## 5 Discussion  
### Application Testing  
The application testing results, presented in Table 2, indicate that the total average implementation time of all scenarios in the Patient group (G1) was the longest and amounted to 16 min and 18 s. Caregivers (G2) completed the scenarios in an average time of 13 min and 18 s, while Educators (G3) took 11 min and 54 s. This shows that the most efficient users of the T1 DCoach application were Educators. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Values**} & \multicolumn{3}{c}{**G1—Patients**} & \multicolumn{3}{c}{**G2—C caregivers**} & \multicolumn{3}{c}{**G3—Educators**} \\ \cline{2-11}  & **Friendliness** & **Ease** & **Satisfaction** & **Friendliness** & **Ease** & **Satisfaction** & **Friendliness** & **Ease** & **Satisfaction** \\ \hline Max & 5.0 & 5.0 & 5.0 & 5.0 & 5.0 & 5.0 & 5.0 & 5.0 & 5.0 \\ \hline Min & 3.0 & 3.0 & 1.0 & 3.0 & 2.0 & 3.0 & 3.0 & 3.0 \\ \hline Avg & 4.2 & 3.4 & 3.3 & 4.3 & 3.5 & 4.0 & 4.3 & 3.5 & 4.2 \\ \hline Deviation & 0.7 & 0.7 & 1.1 & 0.7 & 1.1 & 0.8 & 0.7 & 0.7 & 0.6 \\ \hline \hline \end{tabular} (*) on a scale: 1—very small,..., 5—very big.  
\end{table} 
Table 10: Score values for additional questions for groups G1, G2 and G3 (*). \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Participant** & **Q1** & **Q2** & **Q3** & **Q4** & **Q5** & **Q6** & **Q7** & **Q8** & **Q9** & **Q10** & **SUS** \\ \hline P1 & 5 & 2 & 4 & 2  
The results presented in Tables 3-5 concern metrics that determine the cognitive effort put in by research participants when implementing the scenarios. In the case of the number of fixations and fixation duration, higher levels of these indicators indicate greater cognitive effort. The number of blinks is interpreted differently--the lower the number of blinks, the greater the cognitive effort. The results regarding the average number of fixations (Table 3) for all scenarios show that the most fixations occurred in the group of patients (G1)--2735.9. In the Educators group (G3), there were an average of 2394.3 of these. The fewest fixations occurred in the Caregiver group (G2)--an average of 2276.4. The average fixation duration (Table 4) during the implementation of all scenarios was almost the same in the Patient (G1) and Caregiver (G2) groups and amounted to 298.3 ms and 292.2 ms, respectively. Much shorter fixations occurred in Educators (G3) and lasted on average 198.5 ms. In turn, the average number of blinks (Table 5) during the implementation of the scenarios was 158.2 in the group of patients (G1). There were 119.7 of them in the Caregiver group (G2). The highest number of blinks, i.e., 202.7, occurred in the Educators group (G3). The average success rate of scenario implementation (Table 6) was clearly lower in the group of patients (G1) than in the groups of caregivers (G2) and educators (G3) and amounted to 57.7%, 81.0% and 84.3%, respectively, for the individual groups. All participants had the greatest problems with completing the tasks in scenario S6 (changing insulin pump settings) and in scenario S7 (reviewing achievements and the scoreboard). In the Patients group (G1), the average success rate of these scenarios was 27.5% and 25.0% for S6 and S7, respectively. This result was much lower than in the groups of Caregivers (G2) and Educators (G3). This result is consistent with the practice of T1D treatment--children do not change the insulin pump settings themselves due to the high complexity and responsibility of this process [50]. The results of thinking aloud allowed us to identify three groups of problems: critical, important and unimportant.