# Extended Reality in Applied Sciences Education: A Systematic Review
## 3 Results
### Impact of XR Technology Usage Frequency on Short-Term and Long-Term Learning Outcomes
When the usage frequency increased to 2-5 times, enhanced learning experience/motivation was mentioned in 14 studies ([7,11,12,23,33,37,39,41,53,54,58,59,61]), improved knowledge in 13 studies ([7,11,12,23,33,37,39,41,53,54,58,61]), learning efficiency in 10 studies, and increased satisfaction in 10 studies ([11,23,33,37,38,53,54,58,59,61]). For usage beyond six times but less than an entire semester, enhanced learning experience/motivation was mentioned in seven studies ([20,25,27,40,49,57,62]), improved knowledge was noted in seven studies ([20,25,27,40,49,57,62]), learning efficiency in five studies ([20,25,40,49,57]), and increased satisfaction in four studies ([27,40,57,62]). Finally, in cases of continuous application throughout an entire semester, enhanced learning experience/motivation was mentioned in 13 studies ([13,17,18,22,28,31,34,35,36,43,44,56,65]), increased satisfaction was mentioned in 12 studies ([13,17,18,22,28,31,34,35,36,43,44,65,63,44,65]), learning efficiency was noted in 7 studies ([13,17,28,31,43,44,56,6,13]), and improved knowledge in 10 studies ([13,17,22,28,31,34,35,43,44,65,65]). These findings suggest that the use of XR technologies during mid-term phases may face challenges such as \"loss of novelty\" or \"insufficient alignment with instructional models\", which could lead to underrepresentation in research. However, the upper section of Figure 8, although reflecting fewer studies overall, reveals distinct trends in how the duration of XR technology intervention influences both long-term and short-term learning outcomes, highlighting two additional patterns related to extended XR usage:  
* Case B: positive or sustained long-term outcomes  
A subset of longer-term interventions reported continued improvements in participation, memory retention, and learning confidence. When the usage frequency increased  
Figure 8: Relationship between XR technology usage frequency and learning outcomes: differentiating short-term and long-term achievements across varying application durations. to 2-5 times, participation was highlighted in five studies ([7; 37; 38; 53; 58]), while memory retention ([12; 23; 33; 61]) and learning confidence ([33; 38; 41; 54]) were mentioned in four studies each. Similarly, during semester-long applications, five studies reported increased participation ([28; 31; 34; 35; 65]), four studies noted improvements in memory retention ([28; 31; 34; 43]), while learning confidence was documented in only one study ([22]). * Case C: inconclusive or diminishing long-term outcomes  
Not all studies on extended XR usage demonstrated consistent learning gains. For instance, when XR technologies were applied more than six times but for less than an entire semester, participation ([20; 40]) and learning confidence ([27; 40; 57]) were mentioned in only two and three studies, respectively, with no studies reporting improvements in memory retention. Moreover, even among semester-long interventions, only a small number of studies reported significant effects--five studies documented increased participation ([28; 31; 34; 35; 65]), four studies addressed improved memory retention ([28; 31; 34; 43]), and one study noted enhanced learning confidence ([22]). These findings indicate that while prolonged XR usage may support certain long-term benefits, it does not necessarily enhance all learning outcomes uniformly. The results suggest that Case A is well-supported by numerous short-term studies, highlighting XR's ability to enhance immediate engagement and motivation. However, Cases B and C demonstrate that the long-term impact of XR is less frequently examined and can yield mixed findings. This underscores the need for additional longitudinal research, as long-term learning outcomes may be influenced by other limiting factors.