Presence is a defining element of virtual reality (VR), but it is also increasingly used when assessing mixed reality (MR) experiences. The increased interest in measuring presence in MR and recent works underpinning the specific nature of presence in MR raise the question of the current state and practice of assessing presence in MR. To address this question, we present an analysis of more than 320 studies that report on presence measurements in MR. Our analysis showed that questionnaires are the dominant measurement but also identify problematic trends that stem from the lack of a generally agreed-upon concept or measurement for presence in MR. More specifically, we show that using measurements that are not validated in MR or custom questionnaires limiting the comparability of results is commonplace and could contribute to a looming replication crisis in an increasingly relevant field.

Presence, or the experience of being present in a computer-generated environment, is a defining element of virtual reality. While there are different methodologies to measure presence, questionnaires remain the most popular, particularly the Igroup Presence Questionnaire (IPQ). In this paper, we analyse the results of over 20 years of IPQ usage to develop a new comparative means of reporting presence scores and comparing them across existing and future work. We additionally report on correct and problematic usage of the questionnaire and, through this, present guidelines on how to administer the IPQ in future to aid further analysis. Finally, we present a new web-based tool to streamline the analysis and reporting of IPQ results, which we hope will facilitate more standardised usage of the questionnaire in future research.

Virtual Reality (VR) headsets can open opportunities for users to accomplish complex tasks on large virtual displays using compact and portable devices. However, interacting with such large virtual displays using existing interaction techniques might cause fatigue, especially for precise manipulation tasks, due to the lack of physical surfaces. To deal with this issue, we explored the design of VXSlate, an interaction technique that uses a large virtual display as an expansion of a tablet. We combined a user’s head movements as tracked by the VR headset, and touch interaction on the tablet. Using VXSlate, a user head movements positions a virtual representation of the tablet together with the user’s hand, on the large virtual display. This allows the user to perform fine-tuned multi-touch content manipulations. In a user study with seventeen participants, we investigated the effects of VXSlate on users in problem-solving tasks involving content manipulations at different levels of difficulty, such as translation, rotation, scaling, and sketching. As a baseline for comparison, off-the-shelf touch-controller interactions were used. Overall, VXSlate allowed participants to complete the task with completion times and accuracy that are comparable to touch-controller interactions. After an interval of use, VXSlate significantly reduced users’ time to perform scaling tasks in content manipulations, as well as reducing perceived effort. We reflected on the advantages and disadvantages of VXSlate in content manipulation on large virtual displays and explored further applications within the VXSlate design space.

Many categories of the illusion of self-motion have been widely studied with the potential support of virtual reality. However, the effects of directly and indirectly powering the movement on the possibility of perceiving changes in moving speed and their relationship with sensory feedback on users' speed change perception have not been investigated before. In this paper, we present the results of our user study on the difference in perceiving changes in moving speed between two different movement techniques: "pedaling" and "throttling". We also explore the effects of different velocity gains, accelerations and speeds of airflow, and their interactions with the movement techniques on users' perception of speed changes in addition to user performance and perception. We built a bike simulator that supports both of the movement techniques and provides sensory feedback. In general, "pedaling" gave users more possibility to perceive changes in moving velocity than "throttling".

Many techniques for visualization and interaction that potentially increase user performance have been studied in the growing field of virtual reality. However, the effects of virtual-arm representations on users' performance and perception in selection tasks have not been studied before. This paper presents the results of a user study of three different representations of the virtual arm: "hand only," "hand+forearm," and "whole arm" which includes the upper arm. In addition to the representations' effects on performance and perception in selection tasks, we investigate how the users' performance changes depending on whether collisions with objects are allowed or not. The relationship between the virtual-arm representations and the senses of agency and ownership are also explored. Overall, we found that the "whole arm" condition performed worst.

The reduced gravity experienced in lunar or Martian surfaces can be simulated on the earth using a cable-driven system, where the cable lifts a person to reduce his or her weight. This paper presents a novel cable-driven system designed for the purpose. It is integrated with a head-mounted display and a motion capture system. Focusing on jump motion within the system, this paper proposes to scale the jump and reports the experiments made for quantifying the extent to which a jump can be scaled without the discrepancy between physical and virtual jumps being noticed by the user. With the tolerable range of scaling computed from these experiments, an application named retargeted jump is developed, where a user can jump up onto virtual objects while physically jumping in the real-world flat floor. The core techniques presented in this paper can be extended to develop extreme-sport simulators such as parasailing and skydiving.