Abstract:

Extended realities are becoming more influential, not only in business but also in educational contexts. In some educational fields, HMD-MR (Mixed Reality used with head-mounted displays) is already being used successfully. It has key features such as a comprehensive understanding of the environment and of the user. Furthermore, HMD-MR offers a high degree on adaptivity and thus provides important advantages, especially in educational settings.

In order to extend the benefits of HMD-MR to additional educational fields, it is necessary to investigate a successful entry into HMD-MR, both for learners and for teachers. Regarding the cognitive load theory, the initial contact with such a new and complex technology should be designed in such a way that cognitive load is taken into account and cognitive overload is avoided. For this purpose, the study of Kockord and Bodensiek was replicated with a larger sample, focusing on cognitive load of the participants.

To measure cognitive load during the first contact with HMD-MR, n=21 participants with little to no prior knowledge about extended realities first perform three tasks with physically present foam dice. After each of these three tasks, they answer four questionnaire items on cognitive load regarding the respective task. In the end, a more detailed questionnaire elicits the cognitive load of all three tasks combined as well as the prior knowledge regarding extended realities. Following this first part of the study, each participant performs the same three tasks again, but this time with virtual dice using HMD-MR and gesture control. Again, the same items on cognitive load are queried after each of the virtual tasks.

When the average scores on total cognitive load are compared, it becomes clear that there is a significantly higher cognitive load when using HMD-MR than without. Although the tasks are already known before using HMD-MR, the cognitive load does increase. Due to the applied study design, this increase should be essentially due to the change of interaction methods from conventional non-MR interactions to gesture control using HMD-MR. While the overall cognitive load of this replication study is slightly higher compared to the baseline study, the increase from the non-MR tasks to the HMD-MR tasks is similar. So far, the baseline study is supported.

In addition to total cognitive load, this study also examines the three different types of cognitive load. ICL (intrinsic cognitive load) increases by about 40% when switching from ‘natural’ interaction methods with foam dice to gesture control with virtual dice using HMD-MR. GCL (germane cognitive load) increases by about 30% when switching between the previously mentioned interaction methods. ECL (extraneous cognitive load) decreases slightly by about 10%.

When comparing the baseline and the replication study regarding the three types of cognitive load, considerable differences emerge: Although ICL increases most in both studies, it does to a much lesser extend in the replication. GCL increases more in the replication and ECL even decreases slightly in contrast to the previous considerable increase. The additional four items on cognitive load after each task support the previously mentioned results of the replication study. The reason for the partial deviation has not yet been finally clarified. Furthermore, it is questionable why the largest increase of both studies takes place in ICL and not in ECL or GCL.

Keywords:

Mixed Reality, Extended Reality, Educational Technology, Cognitive Load.