# Immersive Tools in Engineering Education--A Systematic Review
## 4 Discussion
### Cross-Discipilinary Studies in STEM  
Six out of the thirty-one articles included in this review are on different serious games from various areas of STEM (two) [21; 37], tech/science (one) [46], tech/engineering (two) [12; 27], and engineering/science (one) [32]. These articles demonstrate the potential to integrate multiple areas of knowledge simultaneously. They report a significant increase in engagement and motivation across all domains while learning the respective topics, a positive and significant way to test knowledge and apply new concepts [46]. The advantage of combining different STEM areas into a serious game is the games' ease and realism, which can be related to real-life scenarios that a future engineer will encounter in their working life. With these in mind, students can learn in a more engaging environment. An example of this is seen in the study of [PERSON] et al. [32], where science and engineering are integrated into a serious game teaching participants to apply theoretical scientific principles related to combustion and gasification in hydrogen production to practical engineering challenges/situations. Participants design and optimize a hydrogen production facility and must consider key engineering concepts such as site selection, infrastructure requirements, and process efficiency. This approach directly connects fundamental concepts in thermodynamics, reaction kinetics, and environmental assessment to real-world engineering decisions. The limitations are constrained to those seen in specific STEM areas. Table 4 allows for direct comparison across STEM fields. While serious games under science and engineering are easier to create due to their real-world applicability, technological and mathematical games are harder due to their abstract and theoretical base. All the fields present limitations and key points that should be considered to obtain the best results possible during SG creation. Regarding the best immersive technology to be used for each type of field, the more practical fields are better for the usage of VR/AR, while for the more theoretical ones, like mathematics, 3D should be the way to go. In the case of technology, AR can also be seen as a valid option for code studying or cybersecurity threats. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**STEM Field**} & **Difficulty in** & **Real-World** & **Limitations** & **Key Points to Enhance** & **Best Immersive Tech** \\  & **Creating the SG** & **Applications** & & **Serious Games** & **Test** \\ \hline \multirow{4}{*}{Science} & Low to & Virtual labs/ & Lacks stress; & Pre-game tutorials, immersive scenarios, & \\  & Medium & simulations & high visual quality needed & stress simulation, multi-angle & VR \\ \hline \multirow{2}{*}{Technology} & \multirow{2}{*}{High} & Cybersecurity, & \multirow{2}{*}{Abstract code is hard to visualize} & Real-world tasks, & \\  & & Programming & & & simplified interaction, structured logic flow & AR \\ \hline \multirow{4}{*}{Engineering} & \multirow{4}{*}{Low to} & Construction, & \multirow{4}{*}{Inconsistent difficulty, unclear guidance, and a few scenario, branches} & \multirow{4}{*}{Multi-solution paths, progressive levels, } & \multirow{4}{*}{VR/AR} \\  & & & & & \\ \cline{1-1}  & & & & & \\ \cline{1-1}  & & & & & \\ \hline \multirow{4}{*}{Math} & \multirow{2}{*}{High} & Visualizing abstract concepts & Difficult to visualize theory & Adaptive difficults, instant feedback, and collaborative RPG setup & \multirow{2}{*}{3D} \\ \hline \hline \end{tabular}
\end{table} 
Table 4: STEM field comparison. Based on the findings in Table 4, it is possible to set a set of design features that contribute to achieving the full potential of immersive tools used in serious games. A definition of objectives and tasks which gives clear instructions to the participant is critical to reduce possible participant frustration. Also, having a gradual difficulty increase across levels is important for the same reason.