## 3 Results and Discussion
### WCAG Compliance Analysis  
The results obtained from the compliance check are presented in Table 2 and discussed taking into account four WCAG areas: perceivable, operable, understandable, and robust. Moreover, the number of distinct problems categories and total number of problems detected in each test case were calculated. The authors understand that the figures presented in Table 2 closely depend on the content of the webpages; nevertheless, they show the common accessibility problems that should be expected for the particular environments. Each column within the \"visual programming environments\" group contains the number of problems (errors and warnings) detected during the WCAG assessment. The columns holding the results for test cases, where an application visual code was embedded in the code editor of a visual programming environment, include problems related to the visual code presentation and problems related to the environment interface. Each section devoted to the particular environment includes a \"total\" column, which is the \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c} \hline \hline  & & \multicolumn{10}{c}{**Visual Programming Environment**} \\ \cline{3-14}
**Accessibility Problem** & \multicolumn{10}{c}{**Scratch**} & \multicolumn{10}{c}{**App Inventor**} & \multicolumn{10}{c}{**StarLogo**} \\ \cline{3-14}
**1** & **(Error) Empty form label** & 0 & 0 & 0 & 0 & 0 & 36 & 10 & 8 & 7 & 61 & 0 & 0 & 0 & 0 & 0 & 0 \\
2 & **(Error) Empty link** & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 1 & 1 & 1 & 1 & 4 \\
3 & **(Error) Empty table header** & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 1 & 1 & 1 & 1 & 4 \\
4 & **(Error) Language missing or invalid** & 0 & 0 & 0 & 0 & 1 & 1 & 1 & 1 & 4 & 1 & 1 & 1 & 1 & 4 \\
5 & **(Error) Linked image missing alternative text** & 1 & 1 & 1 & 1 & 4 & 0 & 0 & 0 & 0 & 5 & 5 & 5 & 5 & 20 \\
6 & **(Error) Missing alternative text** & 51 & 35 & 38 & 34 & 158 & 148 & 244 & 168 & 147 & 707 & 1 & 1 & 1 & 1 & 4 \\
7 & **(Error) Missing form label** & 3 & 4 & 3 & 3 & 13 & 153 & 160 & 153 & 153 & 619 & 174 & 175 & 203 & 156 & 708 \\
8 & **(Error) Spacer image missing alternative text** & 0 & 0 & 0 & 0 & 0 & 93 & 81 & 81 & 81 & 336 & 0 & 0 & 0 & 0 & 0 \\
9 & **(Error) Very low contrast** & 3 & 3 & 3 & 12 & 4 & 5 & 4 & 4 & 17 & 199 & 198 & 228 & 175 & 800 \\
10 & **(Alert) Device-dependent event handler** & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 2 & 2 & 2 & 8 \\
11 & **(Alert) Image with title** & 2 & 2 & 2 & 8 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
12 & **(Alert) Layout table** & 0 & 0 & 0 & 0 & 286 & 318 & 291 & 286 & 1181 & 1 & 3 & 0 & 5 \\
13 & **(Alert) Missing fieldset** & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 1 & 1 & 1 & 4 \\
14 & **(Alert) Missing first level heading** & 0 & 0 & 0 & 0 & 0 & 1 & 1 & 1 & 1 & 4 & 1 & 1 & 1 & 4 \\
15 & **(Alert) No heading structure** & 1 & 1 & 1 & 1 & 4 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\
16 & **(Alert) No page regions** & 0 & 0 & 0 & 0 & 1 & 0 & 0 & 0 & 1 & 0 & 0 & 0 & 0 & 0 \\
17 & **(Alert) Noscript element** & 2 & 2 & 2 & 2 & 8 & 1 & 1 & 1 & 1 & 4 & 0 & 0 & 0 & 0 & 0 \\
18 & **(Alert) Orphaned form label** & 1 & 1 & 1 & 1 & 4 & 0 & 0 & 0 & 0 & 7 & 7 & 7 & 7 & 28 \\
19 & **(Alert) Possible list** & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 1 & 1 & 1 & 1 & 4 \\
20 & **(Alert) Redundant link** & 0 & 0 & 0 & 0 & 13 & 13 & 13 & 13 & 52 & 7 & 7 & 1 & 1 & 16 \\
21 & **(Alert) Redundant title text** & 0 & 0 & 0 & 0 & 9 & 8 & 1 & 0 & 18 & 3 & 3 & 4 & 2 & 12 \\
22 & **(Alert) Select missing label** & 0 & 0 & 0 & 0 & 0 & 4 & 10 & 2 & 2 & 18 & 37 & 36 & 57 & 17 & 147 \\
23 & **(Alert) Tabindex** & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 1 & 1 & 1 & 1 & 4 \\
24 & **(Alert) Unlabeled form control with title** & 0 & 0 & 0 & 0 & 0 & 2 & 3 & 0 & 0 & 5 & 0 & 0 & 0 & 0 & 0 \\
25 & **(Alert) Very small text** & 37 & 20 & 23 & 19 & 99 & 0 & 10 & 0 & 0 & 10 & 3 & 3 & 15 & 3 & 24 \\ \hline Number of distinct problem categories & 7 & 9 & 9 & 9 & 9 & 13 & 14 & 12 & 11 & 15 & 18 & 18 & 18 & 17 & 18 \\ \hline \hline \end{tabular}
\end{table}