# Utilization of a Mobile Application for Motor Skill Evaluation in Children +
## 3 Results  
In this section we will show the results from the data recorded by the app using the materials and following the method explained in the previous section. As mentioned before, we tested three trajectories (Figure 1), with three difficulty modes for each one (Table 1). Since each child repeated the exercise three times for each trajectory and mode, as explained in the Execution phase of Section 2.4, each child performed a total of 27 valid attempts. The first trajectory (Figure 1a) corresponds to a straight line, which is a very simple exercise that can be done with little concentration. Figure 4 shows the boxplot of the error \(E\) made by the children of the six grades. For each grade, the three attempts were considered as different data points. Since each grade had seven or eight students, each box consisted of either 21 or 24 data points. We can see that for all modes, plotted in Figure 4a-c, the median error decreased as the student's grade increased, even though the speed of grades 4 th to 6 th was higher than that of grades 1 st to 3 rd. If we compare the different modes, the error increased with higher speeds (Figure 4a,b) and grew even more when the path disappeared during the exercise (Figure 4c). Moreover, we see that Mode 3 resulted in a higher error for all grades. The boxplot also seems to indicate that the 1 st grade had a significantly larger dispersion (as measured by the IQR) than the rest at Mode 1 and 2, but at Mode 3 the dispersions were more similar. The motor coordination in 1 st grade was not good even for easier modes, which explains this behavior. Figure 5 shows the results for the parabola-like path (Figure 1b). Again, the error at all levels decreased as the grade increased. Comparing the different modes, we observed again that Mode 3 produced higher errors. Regarding the dispersion of values, we again observed a decreasing trend in Modes 1 and 2 as the grade increased. Mode 3 did not present this effect. Figure 6 shows the results for the zigzag path (Figure 1c). The same trend of a reduction in error as the grade increased was observed, but now the dispersion values were very different at all modes. Figure 4: Error in cm as a function of school grade for the straight-line path for different difficulty modes: (**a**) Mode 1; (**b**) Mode 2; (**c**) Mode 3. Boxes represent the data between Q1 and Q3. The two whiskers represent the data below Q1 and above Q3. The plus sign represents outliers below Q1 \(-\)1.5 IQR or above Q3 \(+\)1.5 IQR, with IQR \(=\) Q3 \(-\) Q1 being the interquartile range. The red line inside the box represents the median. Figure 5: Error in cm as a function of school grade for the parabola-like path for different difficulty modes: (**a**) Mode 1; (**b**) Mode 2; (**c**) Mode 3. Boxes represent the data between Q1 and Q3. The two whiskers represent the data below Q1 and above Q3. The plus sign represents outliers below Q1 \(-\)1.5 IQR or above Q3 \(+\)1.5 IQR and the circle sign falling below Q1 \(-\) 3 IQR or above Q3 \(+\) 3 IQR, with IQR \(=\) Q3 \(-\) Q1 being the interquartile range. The red line inside the box represents the median. Finally, Figure 7 shows the results for the different paths: line, Figure 7a, parabola, Figure 7b, and zigzag, Figure 7c. In each figure, the data corresponding to the three modes and the three attempts have been grouped together. Therefore, taking into account our sample of seven to eight participants per grade, each box consists of 63-72 values. In general, we can see that the median decreased with the grade for the three levels. The dispersion for Level 1 was smaller than for the other levels for the 1 st, 2 nd and 3 rd grades. We can also see that Level 3 presented higher errors, since a path with changes in the direction of the trajectory results in more motor difficulty, especially for the first two grades. It is convenient to remark that the differences between the third and the fourth year for all paths were smaller due to the higher speed used for the same mode in the 4 th to 6 th grades.