# Transforming Interactive Educational Content into Immersive Virtual Reality Learning Objects
## 2 Related Works
Immediately after the word memorization, each participant was prompted with Spanish words which they had to translate to English. They had to complete the same test exactly after a week. The results showed that text-only participants outperformed both IVR groups in the immediate post-test. On the other hand, the test results after a week showed that the number of recalled words from the text-only and IVR with kinesthetic groups were essentially the same, while the IVR without kinesthetic group results were even worse. Although IVR did not surpass the results of a more traditional way of learning, the authors highlighted that overall, the retention rate of words in the kinesthetic IVR was better than the text-only group. [PERSON] et al. 's work [32] presented an empirical evaluation comparing the use of an IVR kinesthetic learning application with traditional training using slides, photos, and videos for industrial hydraulics machine maintenance training. The training application used in the comparison was developed for the Oculus Quest 1 and 2 platforms using the Unity3D game engine. Within the application, a virtual environment was built replicating a real-life hydraulic power unit. Three maintenance tasks were prepared for the training which included changing the pressure filter, offline filter, and inspecting the accumulator pressure. These tasks were designed based on kinesthetic learning. To complete them, trainees had to follow real-life procedures and perform real-like actions on the task relevant components of the power unit by interacting with them with physical hand movements and virtual tools. To use a tool, a trainee must first pick it up by moving their hand close to the tool and pressing and holding the Oculus Quest controller's trigger button to grip it. Then, while holding the tool and keeping it close to a component, the trainee can physically move their hand in a way that mimics a real use of the tool. As an example, the authors describe the use of a virtual spanner where a trainee would pick up the spanner and, while maintaining contact between the spanner's head and a correct bolt, they would motion the hand back and forth to use it. For their study, [PERSON] et al. [32] recruited 2 groups of participants. One group was made up of university students with various degrees of experience. The other group was made up of industry professionals with prior experience in the field. For the student group, a between-subject design was used, so the group was split into two additional subgroups where one subgroup received training through the IVR application while the other one received training in the traditional way through slides, photos, and component samples. The industry group was not split and received both types of training with reduced time duration and learning content for each of the types. For the comparison, data were collected through training experience and environment, and satisfaction and self-confidence in learning surveys, educational practices questionnaire, NASA task load index, practical performance of the maintenance task assessment, and a sense of presence and sense of embodiment assessments. According to the analyzed results, the authors concluded that there was no significant improvement in maintenance task completion performance between training with the IVR training application and traditional training. On the other hand, the authors highlighted that the participants from the student IVR subgroup felt less time-pressured when learning than the participants from the traditional subgroup, stating that more training could be achieved when using IVR. Research by [PERSON] et al. [33] presents a brief study and an IVR training solution that uses electrical muscle stimulation to give feedback to a trainee. The concept of the solution is to help and guide trainees through any virtual training scenario task by providing them with cues and hints using haptic feedback through electrical muscle stimulation.