## 5 Results
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Ref.** & **Research Method** & **Main Variables** & **Measurement Tools—Research Tools** \\ \hline
[192] & Mixed & Students’ viewpoints and insights & Ad hoc questionnaire \\ \hline
[193] & Quantitative & Students’ knowledge retention & 20 question quiz \\ \hline
[194] & Quantitative & Students’ ability to write the English letters & Ad hoc survey \\ \hline
[195] & Qualitative & Students’ evaluation of the use of gamified augmented reality in binary lessons & Observations \\ \hline
[196] & Mixed & Learning value and usability & System Usability Scale (SUS) [222], interviews, and usage data of the application \\ \hline
[197] & Quantitative & Students’ engagement, learning outcomes, task completion rate, and final grade & Collection of quantitative data from the final grade and the overall learning path during the experiment \\ \hline
[198] & Qualitative & Specialists’ inputs and opinions & Observations and scoring rubric \\ \hline
[199] & Quantitative & Learning gains, outcomes, control and joy & 9-item questionnaire adopted from [226] \\ \hline
[200] & Quantitative & Students’ motivation and learning results & Pre-test and post-test ad hoc questionnaires \\ \hline
[201] & Quantitative & Higher education professors’ viewpoints & Ad hoc questionnaire regarding students’ demographic information, prior knowledge, engagement, and use of mobile devices within the classroom \\ \hline
[202] & Qualitative & Students’ viewpoints and perception of joy & Observation reports and transcripts \\ \hline
[203] & Qualitative & Students’ viewpoints & Video recordings and interviews \\ \hline
[204] & Mixed & Learners’ engagement and the application functionality and features & Game analytics, video recordings, and photographs of learners, artifacts, and pre- and post-assessment \\ \hline
[205] & Qualitative & Teachers’ viewpoints & Interviews \\ \hline
[206] & Quantitative & Students’ opinions & 16-item ad hoc questionnaire \\ \hline
[207] & Quantitative & The effect of different augmented reality and guiding strategy types on learning performance and motivation & Prior knowledge test, performance test, and ad hoc questionnaire adapted from the Motivated Strategies for Learning Questionnaire (MSLQ) [227] \\ \hline
[208] & Quantitative & Main factors that motivate participants to play and urge them to continue playing & Ad hoc survey \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._ \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Ref.** & **Application Name** & **Development Tools** & **Operating System** & **Device** & **Gamification Elements** \\ \hline
[81] & Explorez & ARIS & iOS & Mobile devices & Game-like features, badges, and quests \\ \hline
[137] & HoloMusic XP & Vuforia & Windows Holographic OS & Microsoft & Scores and points \\ \hline
[138] & BATIK-AR & ASSEMBLR Studio & Android & Mobile devices & Points and badges \\ \hline
[139] & n/a & n/a & n/a & Mobile devices & Game-like features \\ \hline
[140] & Microorganisms & Unity, Autodesk & & & \\  & & 3 Ds Max, Vuforia & Android & Mobile devices & Quiz questions, timer, and scores \\  & & & and Firebase & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Empirical studies: Application development information and gamification elements.