# Web-Based Serious Games and Accessibility: A Systematic Literature Review
## 3 Method Applied for Systematic Literature Review
### Search Strategy  
Primary studies were identified by a query string derived from the research questions. Based on the research questions in Table 1, PICO was implemented as follows:  
* Population: published studies. * Intervention: accessibility, web-based serious games. * Comparison: selected studies by disability, accessibility standard-based, type of research, assistive technologies, and use of external devices. * Outcome: published studies on accessibility and web-based serious games. Built on PICO, we created the query string, as presented in Table 2. The search was conducted on 6 June 2020, and the authors selected four academic research databases used in engineering to retrieve primary information: (1) ACM Digital Library; (2) IEEE Xplore; (3) Scopus, and (4) Web of Science (WOS). The query strings for each chosen source were defined from the search terms connected by Boolean AND/OR operators. Additionally, the asterisk (*) wildcard was used to include both the singular and plural form of each term. Table 1 shows the selected database, the query string, and the number of studies extracted. The query string was applied to the title of the publication with the keywords: \"serious\", \"game*\", and \"accessi*\". Similar search syntax was applied across the four selected sources for consistency; the period under review included studies published between 2000 and 2020. We used equivalent strings that seek to locate the same articles, but each database has its specific syntax. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Database** & **String Search** & **Number of Studies** \\ \hline  & [Publication Title: accessi\({}^{\sharp}\)] AND [Publication Title: serious] AND [Publication Date: & \\  & (01/(20200 TO 05/31/2020)) & \\
**ACM Digital Library** & [Publication Title: accessi\({}^{\sharp}\)] AND [Publication Title: game\({}^{\sharp}\)] AND [Publication Date: & 92 \\  & (01/01/2000 TO 05/31/2020)] & \\ \hline
**IEEE Xplore** & ((\({}^{\sharp}\)Document Title\({}^{\diamond}\): accessi\({}^{\sharp}\) serious) OR “Document Title\({}^{\diamond}\): accessi\({}^{\sharp}\) game\({}^{\star}\)) & 25 \\ \hline Scopus & TITLE (accessi\({}^{\sharp}\)) AND (TITLE (serious) OR TITLE (game\({}^{\sharp}\))) & 190 \\ \hline
**Web of Science** & TI = (accessi\({}^{\sharp}\) serious) OR TI = (accessi\({}^{\sharp}\) game\({}^{\star}\)) & 169 \\ \hline \multicolumn{3}{c}{**Total studies number**} & **476** \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Query string applied. \begin{table}
\begin{tabular}{l l l} \hline \hline \(\mathbf{N}^{\circ}\) & **Quality Assessment Questions** & **Answer** \\ \hline QA1 & Is serious games accessibility detailed in the paper? & (+1) Yes/(+0) No \\ \hline QA2 & Is the serious games accessibility evaluation method specified in the paper? & (+1) Yes/(+0) No \\ \hline QA3 & Does the paper discuss any findings of serious games accessibility evaluation? & (+1) Yes/(+0) No \\ \hline QA4 & Are standard serious games accessibility errors described in the results? & (+1) Yes/(+0) No \\ \hline QA5 & Is the journal or the conference where the paper was published indexed in SIR? & (+1) if it is ranked Q1, (+0.75) if it is ranked Q2, (+0.50) if it is ranked Q3, (+0.25) if it is ranked Q4, (+0.0) if it is not indexed.