Jan-Niklas Voigt-Antons (Immersive Reality Lab, University of Applied Sciences Hamm-Lippstadt, Germany)
Tanja Kojić (Quality and Usability Lab, Technische Universität Berlin, Germany)
Tobias Hoßfeld (University of Würzburg, Germany)
Christian Timmerer (Alpen-Adria-Universität (AAU) Klagenfurt and Bitmovin Inc., Austria)
Bringing theories and measurement techniques up to date
Development of technology for immersive multimedia experiences
Immersive multimedia experiences, as its name is suggesting are those experiences focusing on media that is able to immerse users with different interactions into an experience of an environment. Through different technologies and approaches, immersive media is emulating a physical world through the means of a digital or simulated world, with the goal of creating a sense of immersion. Users are involved in a technologically driven environment where they may actively join and participate in the experiences offered by the generated world [White Paper, 2020]. Currently, as hardware and technologies are developing further, those immersive experiences are getting better with the more advanced feeling of immersion. This means that immersive multimedia experiences are exceeding just the viewing of the screen and are enabling bigger potential. This column aims to present and discuss the need for an up to date understanding of immersive media quality. Firstly, the development of the constructs of immersion and presence over time will be outlined. Second, influencing factors of immersive media quality will be introduced, and related standardisation activities will be discussed. Finally, this column will be concluded by summarising why an updated understanding of immersive media quality is urgent.
Development of theories covering immersion and presence
One of the first definitions of presence was established by Slater and Usoh already in 1993 and they defined presence as a “sense of presence” in a virtual environment [Slater, 1993]. This is in line with other early definitions of presence and immersion. For example, Biocca defined immersion as a system property. Those definitions focused more on the ability of the system to technically accurately provide stimuli to users [Biocca, 1995]. As technology was only slowly capable to provide systems that are able to generate stimulation to users that can mimic the real world, this was of course the main content of definitions. Quite early on questionnaires to capture the experienced immersion were introduced, such as the Igroup Presence Questionnaire (IPQ) [Schubert, 2001]. Also, the early methods for measuring experiences are mainly focused on aspects of how good the representation of the real world was done and perceived. With maturing technology, the focus was shifted more towards emotions and more cognitive phenomena besides the basics stimulus generation. For example, Baños and colleagues showed that experienced emotion and immersion are in relation to each other and also influence the sense of presence [Baños, 2004]. Newer definitions focus more on these mentioned cognitive aspects, e.g., Nilsson defines three factors that can lead to immersion: (i) technology, (ii) narratives, and (iii) challenges, where only the factor technology is a non-cognitive one [Nilsson, 2016]. In 2018, Slater defines the place illusion as the illusion of being in a place while knowing one is not really there. This is a focus on a cognitive construct, removal of disbelieve, but still leaves the focus of how the illusion is created mainly on system factors instead of cognitive ones [Slater, 2018]. In recent years, more and more activities were started to define how to measure immersive experiences as an overall construct.
Constructs of interest in relation to immersion and presence
This section discusses constructs and activities that are related to immersion and presence. In the beginning, subtypes of extended reality (XR) and the relation to user experience (UX) as well as quality of experience (QoE) are outlined. Afterwards, recent standardization activities related to immersive multimedia experiences are introduced and discussed.
Moreover, immersive multimedia experiences can be divided by many different factors, but recently the most common distinctions are regarding the interactivity where content can be made for multi-directional viewing as 360-degree videos, or where content is presented through interactive extended reality. Those XR technologies can be divided into mixed reality (MR), augmented reality (AR), augmented virtuality (AV), virtual reality (VR), and everything in between [Milgram, 1995]. Through all those areas immersive multimedia experiences have found a place on the market, and are providing new solutions to challenges in research as well as in industries, with a growing potential of adopting into different areas [Chuah, 2018].
While discussing immersive multimedia experiences, it is important to address user experience and quality of immersive multimedia experiences, which can be defined following the definition of quality of experience itself [White Paper, 2012] as a measure of the delight or annoyance of a customer’s experiences with a service, wherein this case service is an immersive multimedia experience. Furthermore, while defining QoE terms experience and application are also defined and can be utilized for immersive multimedia experience, where an experience is an individual’s stream of perception and interpretation of one or multiple events; and application is a software and/or hardware that enables usage and interaction by a user for a given purpose [White Paper 2012].
As already mentioned, immersive media experiences have an impact in many different fields, but one, where the impact of immersion and presence is particularly investigated, is gaming applications along with QoE models and optimizations that go with it. Specifically interesting is the framework and standardization for subjective evaluation methods for gaming quality [ITU-T Rec. P.809, 2018]. This standardization is providing instructions on how to assess QoE for gaming services from two possible test paradigms, i.e., passive viewing tests and interactive tests. However, even though detailed information about the environments, test set-ups, questionnaires, and game selection materials are available those are still focused on the gaming field and concepts of flow and immersion in games themselves.
Together with gaming, another step in defining and standardizing infrastructure of audiovisual services in telepresence, immersive environments, and virtual and extended reality, has been done in regards to defining different service scenarios of immersive live experience [ITU-T Rec. H.430.3, 2018] where live sports, entertainment, and telepresence scenarios have been described. With this standardization, some different immersive live experience scenarios have been described together with architectural frameworks for delivering such services, but not covering all possible use case examples. When mentioning immersive multimedia experience, spatial audio sometimes referred to as “immersive audio” must be mentioned as is one of the key features of especially of AR or VR experiences [Agrawal, 2019], because in AR experiences it can provide immersive experiences on its own, but also enhance VR visual information.
In order to be able to correctly assess QoE or UX, one must be aware of all characteristics such as user, system, content, and context because their actual state may have an influence on the immersive multimedia experience of the user. That is why all those characteristics are defined as influencing factors (IF) and can be divided into Human IF, System IF, and Context IF and are as well standardized for virtual reality services [ITU-T Rec. G.1035, 2021]. Particularly addressed Human IF is simulator sickness as it specifically occurs as a result of exposure to immersive XR environments. Simulator sickness is also known as cybersickness or VR/AR sickness, as it is visually induced motion sickness triggered by visual stimuli and caused by the sensory conflict arising between the vestibular and visual systems. Therefore, to achieve the full potential of immersive multimedia experience, the unwanted sensation of simulation sickness must be reduced. However, with the frequent change of immersive technology, some hardware improvement is leading to better experiences, but a constant updating of requirement specification, design, and development is needed together with it to keep up with the best practices.
Conclusion – Towards an updated understanding
Considering the development of theories, definitions, and influencing factors around the constructs immersion and presence, one can see two different streams. First, there is a quite strong focus on the technical ability of systems in most early theories. Second, the cognitive aspects and non-technical influencing factors gain importance in the new works. Of course, it is clear that in the 1990ies, technology was not yet ready to provide a good simulation of the real world. Therefore, most activities to improve systems were focused on that activity including measurements techniques. In the last few years, technology was fast developing and the basic simulation of a virtual environment is now possible also on mobile devices such as the Oculus Quest 2. Although concepts such as immersion or presence are applicable from the past, definitions dealing with those concepts need to capture as well nowadays technology. Meanwhile, systems have proven to provide good real-world simulators and provide users with a feeling of presence and immersion. While there is already activity in standardization which is quite strong and also industry-driven, research in many research disciplines such as telecommunication are still mainly using old questionnaires. These questionnaires are mostly focused on technological/real-world simulation constructs and, thus, not able to differentiate products and services anymore to an extent that is optimal. There are some newer attempts to create new measurement tools for e.g. social aspects of immersive systems [Li, 2019; Toet, 2021]. Measurement scales aiming at capturing differences due to the ability of systems to create realistic simulations are not able to reliably differentiate different systems due to the fact that most systems are providing realistic real-world simulations. To enhance research and industrial development in the field of immersive media, we need definitions of constructs and measurement methods that are appropriate for the current technology even if the newer measurement and definitions are not as often cited/used yet. That will lead to improved development and in the future better immersive media experiences.
One step towards understanding immersive multimedia experiences is reflected by QoMEX 2022. The 14th International Conference on Quality of Multimedia Experience will be held from September 5th to 7th, 2022 in Lippstadt, Germany. It will bring together leading experts from academia and industry to present and discuss current and future research on multimedia quality, Quality of Experience (QoE), and User Experience (UX). It will contribute to excellence in developing multimedia technology towards user well-being and foster the exchange between multidisciplinary communities. One core topic is immersive experiences and technologies as well as new assessment and evaluation methods, and both topics contribute to bringing theories and measurement techniques up to date. For more details, please visit https://qomex2022.itec.aau.at.
[Agrawal, 2019] Agrawal, S., Simon, A., Bech, S., Bærentsen, K., Forchhammer, S. (2019). “Defining Immersion: Literature Review and Implications for Research on Immersive Audiovisual Experiences.” In Audio Engineering Society Convention 147. Audio Engineering Society.
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[Baños, 2004] Baños, R. M., Botella, C., Alcañiz, M., Liaño, V., Guerrero, B., & Rey, B. (2004). Immersion and emotion: their impact on the sense of presence. Cyberpsychology & behavior, 7(6), 734-741.
[Chuah, 2018] Chuah, S. H. W. (2018). Why and who will adopt extended reality technology? Literature review, synthesis, and future research agenda. Literature Review, Synthesis, and Future Research Agenda (December 13, 2018).
[ITU-T Rec. G.1035, 2021] ITU-T Recommendation G:1035 (2021). Influencing factors on quality of experience for virtual reality services, Int. Telecomm. Union, CH-Geneva.
[ITU-T Rec. H.430.3, 2018] ITU-T Recommendation H:430.3 (2018). Service scenario of immersive live experience (ILE), Int. Telecomm. Union, CH-Geneva.
[ITU-T Rec. P.809, 2018] ITU-T Recommendation P:809 (2018). Subjective evaluation methods for gaming quality, Int. Telecomm. Union, CH-Geneva.
[Li, 2019] Li, J., Kong, Y., Röggla, T., De Simone, F., Ananthanarayan, S., De Ridder, H., … & Cesar, P. (2019, May). Measuring and understanding photo sharing experiences in social Virtual Reality. In Proceedings of the 2019 CHI Conference on Human Factors in Computing Systems (pp. 1-14).
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[Toet, 2021] Toet, A., Mioch, T., Gunkel, S. N., Niamut, O., & van Erp, J. B. (2021). Holistic Framework for Quality Assessment of Mediated Social Communication.
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[White Paper, 2012] Qualinet White Paper on Definitions of Quality of Experience (2012). European Network on Quality of Experience in Multimedia Systems and Services (COST Action IC 1003), Patrick Le Callet, Sebastian Möller and Andrew Perkis, eds., Lausanne, Switzerland, Version 1.2, March 2013.
[White Paper, 2020] Perkis, A., Timmerer, C., Baraković, S., Husić, J. B., Bech, S., Bosse, S., … & Zadtootaghaj, S. (2020). QUALINET white paper on definitions of immersive media experience (IMEx). arXiv preprint arXiv:2007.07032.