Researchers

Katja Rogers

Postdoctoral Researcher, Game Audio, VR, Asymmetric Gameplay, Realism, Fidelity, Systematic Reviews

Projects

Exergetic: An innovative digital solution to individually improve physical and cognitive functions using an exergame (video game-based) training in an ecologically valid and safe setting for the geriatric population

SWaGUR: Saskatchewan-Waterloo Games User Research

Developing and Analysing Adaptive, Enjoyable, and Engaging Human-Computer Interfaces

Mitacs: Improving User Experience and Accessibility of Online Medical Test Data via Gameful Design

Developing and Analyzing Immersive Game Technologies and Components for Motivation, Wellbeing, and Guidance

Publications

Year 2020

Game Atmosphere: Effects of Audiovisual Thematic Cohesion on Player Experience and Psychophysiology

@inproceedings{10.1145/3410404.3414245,
author = {Ribeiro, Giovanni and Rogers, Katja and Altmeyer, Maximilian and Terkildsen, Thomas and Nacke, Lennart E.},
title = {Game Atmosphere: Effects of Audiovisual Thematic Cohesion on Player Experience and Psychophysiology},
year = {2020},
isbn = {9781450380744},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3410404.3414245},
doi = {10.1145/3410404.3414245},
abstract = {Game atmosphere and game audio are critical factors linked to the commercial success of video games. However, game atmosphere has been neither operationalized nor clearly defined in games user research literature, making it difficult to study. We define game atmosphere as the emerging subjective experience of a player caused by the strong audiovisual thematic cohesion (i.e., the harmonic fit of sounds and graphics to a shared theme) of video game elements. We studied players' experience of thematic cohesion in two between-subjects, independent-measures experiments (N=109) across four conditions differing in their level of audiovisual thematic fit. Participants' experiences were assessed with physiological and psychometric measurements to understand the effect of game atmosphere on player experience. Results indicate that a lack of thematic fit between audio and visuals lowers the degree of perceived atmosphere, but that while audiovisual thematic dissonance may lead to higher-intensity negative-valence facial events, it does not impact self-reported player experience or immersion.},
booktitle = {Proceedings of the Annual Symposium on Computer-Human Interaction in Play},
pages = {107–119},
numpages = {13},
keywords = {music, player experience, games, dissonance, audio, atmosphere},
location = {Virtual Event, Canada},
series = {CHI PLAY '20}
}

Game atmosphere and game audio are critical factors linked to the commercial success of video games. However, game atmosphere has been neither operationalized nor clearly defined in games user research literature, making it difficult to study. We define game atmosphere as the emerging subjective experience of a player caused by the strong audiovisual thematic cohesion (i.e., the harmonic fit of sounds and graphics to a shared theme) of video game elements. We studied players' experience of thematic cohesion in two between-subjects, independent-measures experiments (N=109) across four conditions differing in their level of audiovisual thematic fit. Participants' experiences were assessed with physiological and psychometric measurements to understand the effect of game atmosphere on player experience. Results indicate that a lack of thematic fit between audio and visuals lowers the degree of perceived atmosphere, but that while audiovisual thematic dissonance may lead to higher-intensity negative-valence facial events, it does not impact self-reported player experience or immersion.

JumpVR: Jump-Based Locomotion Augmentation for Virtual Reality

@inproceedings{10.1145/3313831.3376243,
author = {Wolf, Dennis and Rogers, Katja and Kunder, Christoph and Rukzio, Enrico},
title = {JumpVR: Jump-Based Locomotion Augmentation for Virtual Reality},
year = {2020},
isbn = {9781450367080},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3313831.3376243},
doi = {10.1145/3313831.3376243},
booktitle = {Proceedings of the 2020 CHI Conference on Human Factors in Computing Systems},
pages = {1–12},
numpages = {12},
keywords = {vr, jumping, super human, hyper realism, virtual reality, immersion},
location = {Honolulu, HI, USA},
series = {CHI ’20}
}

One of the great benefits of virtual reality (VR) is the implementation of features that go beyond realism. Common "unrealistic" locomotion techniques (like teleportation) can avoid spatial limitation of tracking, but minimize potential benefits of more realistic techniques (e.g. walking). As an alternative that combines realistic physical movement with hyper-realistic virtual outcome, we present JumpVR, a jump-based locomotion augmentation technique that virtually scales users' physical jumps. In a user study (N=28), we show that jumping in VR (regardless of scaling) can significantly increase presence, motivation and immersion compared to teleportation, while largely not increasing simulator sickness. Further, participants reported higher immersion and motivation for most scaled jumping variants than forward-jumping. Our work shows the feasibility and benefits of jumping in VR and explores suitable parameters for its hyper-realistic scaling. We discuss design implications for VR experiences and research.

The Potential Disconnect between Time Perception and Immersion: Effects of Music on VR Player Experience

@inproceedings{10.1145/3410404.3414246,
author = {Rogers, Katja and Milo, Maximilian and Weber, Michael and Nacke, Lennart E.},
title = {The Potential Disconnect between Time Perception and Immersion: Effects of Music on VR Player Experience},
year = {2020},
isbn = {9781450380744},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3410404.3414246},
doi = {10.1145/3410404.3414246},
abstract = {How much music contributes to player experience (PX) in virtual reality (VR) games remains unclear in the games user research literature. A core factor of PX in VR games that has not been studied before (in relation to audio or otherwise) is time perception. Thus, we provide the first empirical exploration of how music affects time perception in a VR game. In a user study (N=64), we investigated the effects of music on PX and time perception (operationalized as retrospective time estimation). Participants retrospectively perceived time to pass significantly quicker in the VR game when music was present, but reported no difference in PX components, including immersion. This contributes to ongoing discourse on the surprising lack of music effects in VR games. Moreover, our results highlight the need to re-conceptualize our understanding of the relationship between time perception and immersion in games.},
booktitle = {Proceedings of the Annual Symposium on Computer-Human Interaction in Play},
pages = {414–426},
numpages = {13},
keywords = {immersion, music, adaptive music, virtual reality, player experience, time perception},
location = {Virtual Event, Canada},
series = {CHI PLAY '20}
}

How much music contributes to player experience (PX) in virtual reality (VR) games remains unclear in the games user research literature. A core factor of PX in VR games that has not been studied before (in relation to audio or otherwise) is time perception. Thus, we provide the first empirical exploration of how music affects time perception in a VR game. In a user study (N=64), we investigated the effects of music on PX and time perception (operationalized as retrospective time estimation). Participants retrospectively perceived time to pass significantly quicker in the VR game when music was present, but reported no difference in PX components, including immersion. This contributes to ongoing discourse on the surprising lack of music effects in VR games. Moreover, our results highlight the need to re-conceptualize our understanding of the relationship between time perception and immersion in games.

Year 2019

Audio Habits and Motivations in Video Game Players

@inproceedings{rogers2019audio,
author = {Rogers, Katja and Weber, Michael},
title = {Audio Habits and Motivations in Video Game Players},
year = {2019},
isbn = {9781450372978},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3356590.3356599},
doi = {10.1145/3356590.3356599},
booktitle = {Proceedings of the 14th International Audio Mostly Conference: A Journey in Sound},
pages = {45–52},
numpages = {8},
keywords = {music, games, player motivations, in-the-wild, audio},
location = {Nottingham, United Kingdom},
series = {AM’19}
}

Game music is increasingly being explored in terms of empirical effects on players, but we know very little about how players actually perceive and use background music in games, and why. We conducted a survey (N=737) to gain an understanding of players' in-the-wild audio habits and motivations, which can inform future research and industry practices regarding game audio design. The results indicate a wide variance in players' estimation of the importance of music in games. Further, we identify and provide evidence for the comparatively new multitasking phenomenon: a substantial number of players who do not listen to games' provided background music, often in favour of additional/parallel media usage. Based on these findings, we discuss implications for game audio design, ground existing common knowledge with empirical support, and delineate future research directions.

Effects of Background Music on Risk-Taking and General Player Experience

@inproceedings{rogers2019effects,
author = {Rogers, Katja and J\"{o}rg, Matthias and Weber, Michael},
title = {Effects of Background Music on Risk-Taking and General Player Experience},
year = {2019},
isbn = {9781450366885},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3311350.3347158},
doi = {10.1145/3311350.3347158},
booktitle = {Proceedings of the Annual Symposium on Computer-Human Interaction in Play},
pages = {213–224},
numpages = {12},
keywords = {player experience, player behaviour, game audio, music, immersion, risk-taking},
location = {Barcelona, Spain},
series = {CHI PLAY ’19}
}
  

Music affects our emotions and behaviour in real life, yet despite its prevalence in games, we have a limited understanding of its potential as a tool to explicitly influence player experience and behaviour in games. In this work, we investigate whether we can affect players' risk-taking behaviour through the presence and attributes of background music. We built a game that operationalizes risk behaviour by repeatedly giving players the choice between a safe but less rewarding course, and a risky but potentially more rewarding course. In a mixed-design user study (N=60), we explored the impact of music presence, tempo, and affective inflection on players' in-game risk behaviour and overall player experience. We found an effect of music presence on risk behaviour in the first playthrough, i.e., in the absence of other prior knowledge about the game. Further, music affect and tempo affected player immersion, as well as experienced mastery and challenge. Based on these findings, we discuss implications for game design and future research directions.

ExerCube vs. Personal Trainer: Evaluating a Holistic, Immersive, and Adaptive Fitness Game Setup.

@inproceedings{martinniedecken2019exercube,
author = {Martin-Niedecken, Anna Lisa and Rogers, Katja and Turmo Vidal, Laia and Mekler, Elisa D. and M\'{a}rquez Segura, Elena},
title = {ExerCube vs. Personal Trainer: Evaluating a Holistic, Immersive, and Adaptive Fitness Game Setup},
year = {2019},
isbn = {9781450359702},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3290605.3300318},
doi = {10.1145/3290605.3300318},
booktitle = {Proceedings of the 2019 CHI Conference on Human Factors in Computing Systems},
pages = {1–15},
numpages = {15},
keywords = {fitness game, exertion game, flow, exercube, adaptivity},
location = {Glasgow, Scotland Uk},
series = {CHI ’19}
}
  

Today's spectrum of playful fitness solutions features systems that are clearly game-first or fitness-first in design; hardly any sufficiently incorporate both areas. Consequently, existing applications and evaluations often lack in focus on attractiveness and effectiveness, which should be addressed on the levels of body, controller, and game scenario following a holistic design approach. To contribute to this topic and as a proof-of-concept, we designed the ExerCube, an adaptive fitness game setup. We evaluated participants' multi-sensory and bodily experiences with a non-adaptive and an adaptive ExerCube version and compared them with personal training to reveal insights to inform the next iteration of the ExerCube. Regarding flow, enjoyment and motivation, the ExerCube is on par with personal training. Results further reveal differences in perception of exertion, types and quality of movement, social factors, feedback, and audio experiences. Finally, we derive considerations for future research and development directions in holistic fitness game setups.

Exploring Interaction Fidelity in Virtual Reality: Object Manipulation and Whole-Body Movements

@inproceedings{rogers2019exploring,
author = {Rogers, Katja and Funke, Jana and Frommel, Julian and Stamm, Sven and Weber, Michael},
title = {Exploring Interaction Fidelity in Virtual Reality: Object Manipulation and Whole-Body Movements},
year = {2019},
isbn = {9781450359702},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3290605.3300644},
doi = {10.1145/3290605.3300644},
booktitle = {Proceedings of the 2019 CHI Conference on Human Factors in Computing Systems},
pages = {1–14},
numpages = {14},
keywords = {games, interaction fidelity, player experience, virtual objects, virtual reality, whole body interaction},
location = {Glasgow, Scotland Uk},
series = {CHI ’19}
}
  

High degrees of interaction fidelity (IF) in virtual reality (VR) are said to improve user experience and immersion, but there is also evidence of low IF providing comparable experiences. VR games are now increasingly prevalent, yet we still do not fully understand the trade-off between realism and abstraction in this context. We conducted a lab study comparing high and low IF for object manipulation tasks in a VR game. In a second study, we investigated players' experiences of IF for whole-body movements in a VR game that allowed players to crawl underneath virtual boulders and "dangle'' along monkey bars. Our findings show that high IF is preferred for object manipulation, but for whole-body movements, moderate IF can suffice, as there is a trade-off with usability and social factors. We provide guidelines for the development of VR games based on our results.

Take Back Control: Effects of Player Influence on Procedural Level Generation

@inproceedings{frommel2019take,
author = {Frommel, Julian and Puschmann, Dietmar and Rogers, Katja and Weber, Michael},
title = {Take Back Control: Effects of Player Influence on Procedural Level Generation},
year = {2019},
isbn = {9781450368711},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3341215.3356288},
doi = {10.1145/3341215.3356288},
booktitle = {Extended Abstracts of the Annual Symposium on Computer-Human Interaction in Play Companion Extended Abstracts},
pages = {371–378},
numpages = {8},
keywords = {control, challenge, autonomy, agency, procedural content generation, pcg, level generation, influence, difficulty},
location = {Barcelona, Spain},
series = {CHI PLAY ’19 Extended Abstracts}
}
  

Many games use procedural content generation (PCG) to create varied game experiences without having to create all content manually. They allow varying degrees of player influence on generation, from retaining all control to giving full control to players over a number of parameters. Despite the prevalence of PCG in commercial games, little research has examined how player influence on PCG parameters affects their experience. We present a preliminary study examining the effect of three degrees of player influence on PCG parameters of game levels, by means of a dungeon crawler game featuring 22 parameters for level design. Participants played the game with varying degrees of control (none, limited, high) over those parameters and reported subjective player experience measures. The results show that degree of influence affects player experience; high control elicits significantly higher autonomy than the other conditions. While future research disentangling agency and challenge is necessary, our preliminary findings suggest that player control over PCG features potentially improves experience by eliciting increased autonomy.

Towards Socially Immersive Fitness Games: An Exploratory Evaluation Through Embodied Sketching

@inproceedings{martinniedecken2019towards,
author = {Martin-Niedecken, Anna Lisa and M\'{a}rquez Segura, Elena and Rogers, Katja and Niedecken, Stephan and Turmo Vidal, Laia},
title = {Towards Socially Immersive Fitness Games: An Exploratory Evaluation Through Embodied Sketching},
year = {2019},
isbn = {9781450368711},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3341215.3356293},
doi = {10.1145/3341215.3356293},
booktitle = {Extended Abstracts of the Annual Symposium on Computer-Human Interaction in Play Companion Extended Abstracts},
pages = {525–534},
numpages = {10},
keywords = {mixed-reality., embodied sketching, exergames, multi-player, social immersion},
location = {Barcelona, Spain},
series = {CHI PLAY ’19 Extended Abstracts}
}
  

Despite many benefits of playing and exercising together in terms of motivation, engagement, and social relationships, many exergames are designed to be single player, while others implement only a facade of social play (e.g., leaderboards). The challenge remains: how can exergames be designed to balance fun, exertion, and social connection? In this work, we ran an embodied sketching activity with multiplayer variations of the Sphery Racer mixed-reality fitness game, allowing us to test physical and social game mechanics. We discuss here: i) preliminary results on how these variations support a rich training and social experience; and ii) the potential of our method to surface interesting design directions. These contributions can inspire others designing in this domain, and support the development of a rich design space for co-located exergames.

Year 2018

Emotion-based Dynamic Difficulty Adjustment Using Parametrized Difficulty and Self-Reports of Emotion

@inproceedings{frommel2018emotion,
author = {Frommel, Julian and Fischbach, Fabian and Rogers, Katja and Weber, Michael},
title = {Emotion-Based Dynamic Difficulty Adjustment Using Parameterized Difficulty and Self-Reports of Emotion},
year = {2018},
isbn = {9781450356244},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3242671.3242682},
doi = {10.1145/3242671.3242682},
booktitle = {Proceedings of the 2018 Annual Symposium on Computer-Human Interaction in Play},
pages = {163–171},
numpages = {9},
keywords = {adapt, dda, emotion, adaptivity, dialogue, self-report, difficulty},
location = {Melbourne, VIC, Australia},
series = {CHI PLAY ’18}
}
  

Research has shown that dynamic difficulty adjustment (DDA) can benefit player experience in digital games. However, in some cases it can be difficult to assess when adjustments are necessary. In this paper, we propose an approach of emotion-based DDA that uses self-reported emotions to inform when an adaptation is necessary. In comparison to earlier DDA techniques based on affect, we use parameterized difficulty to define difficulty levels and select the suitable level based on players' frustration and boredom. We conducted a user study with 66 participants investigating performance and effects on player experience and perceived competence of this approach. The study further explored how self-reports of emotional state can be integrated in dialogs with non-player characters to provide less interruption. The results show that our emotion-based DDA approach works as intended and yields better player experience than constant or increasing difficulty approaches. While the dialog-based self-reports did not positively affect player experience, they yielded high accuracy. Together, these findings indicate our emotion-based approach works as intended and provides good player experience, thus representing a useful tool for game developers to easily implement reliable DDA.

Exploring the Role of Non-Player Characters and Gender in Player Identification

@inproceedings{Rogers2018c,
abstract = {Non-player characters (NPCs) are important for immersion, but how their character design affects player experience has received little attention in previous games research. Related work suggests that NPCs support player identification, which in turn impacts player enjoyment and immersion, but this has not been explored empirically. In a betweensubjects study, we explored effects of NPC design on player experience. In particular, we investigated how biological sex of NPCs and player gender affect identification and NPC interaction. Our results provide first empirical support for NPC design supporting player identification, reveal gender differences in the identification process, and uncover new research questions regarding mediators of the identification process.},
author = {Rogers, Katja and Aufheimer, Maria and Weber, Michael and Nacke, Lennart E.},
booktitle = {Proceedings of the 2018 Annual Symposium on Computer-Human Interaction in Play - CHI PLAY '18 Extended Abstracts},
doi = {10.1145/3270316.3273041},
isbn = {9781450359689},
keywords = {Non-player characters,gender,player identification},
pages = {271--283},
publisher = {ACM},
title = {{Exploring the Role of Non-Player Characters and Gender in Player Identification}},
year = {2018}
}

Non-player characters (NPCs) are important for immersion, but how their character design affects player experience has received little attention in previous games research. Related work suggests that NPCs support player identification, which in turn impacts player enjoyment and immersion, but this has not been explored empirically. In a betweensubjects study, we explored effects of NPC design on player experience. In particular, we investigated how biological sex of NPCs and player gender affect identification and NPC interaction. Our results provide first empirical support for NPC design supporting player identification, reveal gender differences in the identification process, and uncover new research questions regarding mediators of the identification process.

KickAR: Exploring Game Balancing Through Boosts and Handicaps in Augmented Reality Table Football

@inproceedings{Rogers2018b,
author = {Rogers, Katja and Colley, Mark and Lehr, David and Frommel, Julian and Walch, Marcel and Nacke, Lennart E and Weber, Michael},
booktitle = {Proceedings of the SIGCHI Conference on Human Factors in Computing Systems - CHI '18},
doi = {10.1145/3173574.3173740},
publisher = {ACM},
title = {{KickAR : Exploring Game Balancing Through Boosts and Handicaps in Augmented Reality Table Football}},
year = {2018}
}

When player skill levels are not matched, games provide an unsatisfying player experience. Player balancing is used across many digital game genres to address this, but has not been studied for co-located augmented reality (AR) tabletop games, where using boosts and handicaps can adjust for different player skill levels. In the setting of an AR table football game, we studied the importance of game balancing being triggered by the game system or the players, and whether player skill should be required to trigger game balancing. We implemented projected icons to prominently display game balancing mechanics in the AR table football game. In a within-subjects study (N=24), we found players prefer skill-based control over game balancing and that different triggers are perceived as having different fairness. Further, the study showed that even game balancing that is perceived as unfair can provide enjoyable game experiences. Based on our findings, we provide suggestions for player balancing in AR tabletop games.

Textile Manager: Design and Development of a Persuasive Game about Sustainable Textile Production

@inproceedings{rogers2018textile,
author = {Rogers, Katja and Olah, Michael and Weber, Michael},
title = {Textile Manager: Design and Development of a Persuasive Game about Sustainable Textile Production},
year = {2018},
isbn = {9781450356213},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3170427.3188623},
doi = {10.1145/3170427.3188623},
booktitle = {Extended Abstracts of the 2018 CHI Conference on Human Factors in Computing Systems},
pages = {1–6},
numpages = {6},
keywords = {persuasive game, sustainability, behaviour change, textile production, persuasive technology},
location = {Montreal QC, Canada},
series = {CHI EA ’18}
}
  

Textile production is a large and profitable industry that still struggles with issues relating to environmental impact and societal concerns like labour rights. Incorporating sustainable practices to reduce these issues will be highly beneficial for future generations. Potential measures exist on both an industry and company level, as well as in the purchase behaviour of individual consumers. We present Textile Manager, a persuasive game designed to encourage players to consider their own textile-related behaviour. Based on expert interviews, we discerned goals for a persuasive game to create awareness about issues in traditional textile production. Textile Manager presents a proof-of-concept prototype that was evaluated with a pre-post exposure study. We report findings regarding persuasive effect, voluntary information quests, and visualization of consequences for player decisions to contribute towards the persuasive technology research community.

Towards the Visual Design of Non-Player Characters for Narrative Roles

@inproceedings{Rogers2018d,
abstract = {Non-player characters (NPCs) serve important functions for game narratives and influence player immersion. However, the visual design of NPCs for specific narrative roles is often approached by relying on designers' previous experience or guesswork. We contribute to the understanding of player perception of narrative NPC roles in games, by proposing a methodological approach towards the visual design of NPCs to fit specific narrative roles. We demonstrate this approach through the visual design of characters for the three narrative roles of mentor, companion, and enemy. The results of an online survey (n=45) indicate trait expectations towards these narrative roles, and differences therein based on participant gender. Further, the characters were generally perceived as the targeted role based on visual design alone. This method of designing characters for narrative roles is beneficial to both game designers and researchers for further exploring effects of NPCs on player experience.},
address = {Toronto, ON, Canada},
author = {Rogers, Katja and Aufheimer, Maria and Weber, Michael and Nacke, Lennart E.},
booktitle = {Proceedings of Graphics Interfaces 2018},
doi = {10.20380/GI2018.21},
isbn = {9780994786821},
issn = {07135424},
keywords = {Gender,Narrative roles,Non-player characters,Player experience,Trait expectations,Visual design},
pages = {154--161},
title = {{Towards the visual design of non-player characters for narrative roles}},
year = {2018}
}

Non-player characters (NPCs) serve important functions for game narratives and influence player immersion. However, the visual design of NPCs for specific narrative roles is often approached by relying on designers’ previous experience or guesswork. We contribute to the understanding of player perception of narrative NPC roles in games, by proposing a methodological approach towards the visual design of NPCs to fit specific narrative roles. We demonstrate this approach through the visual design of characters for the three narrative roles of mentor, companion, and enemy. The results of an online survey (n=45) indicate trait expectations towards these narrative roles, and differences therein based on participant gender. Further, the characters were generally perceived as the targeted role based on visual design alone. This method of designing characters for narrative roles is beneficial to both game designers and researchers for further exploring effects of NPCs on player experience.

Vanishing Importance: Studying Immersive Effects of Game Audio Perception on Player Experiences in Virtual Reality

@inproceedings{Rogers2018a,
author = {Rogers, Katja and Ribeiro, Giovanni and Wehbe, Rina and Weber, Michael and Nacke, Lennart E},
booktitle = {Proceedings of the SIGCHI Conference on Human Factors in Computing Systems - CHI '18},
doi = {10.1145/3173574.3173902},
publisher = {ACM},
title = {{Vanishing Importance : Studying Immersive Effects of Game Audio Perception on Player Experiences in Virtual Reality}},
year = {2018}
}

Sound and virtual reality (VR) are two important output modalities for creating an immersive player experience (PX). While prior research suggests that sounds might contribute to a more immersive experience in games played on screens and mobile displays, there is not yet evidence of these effects of sound on PX in VR. To address this, we conducted a within-subjects experiment using a commercial horror-adventure game to study the effects of a VR and monitor-display version of the same game on PX. Subsequently, we explored, in a between-subjects study, the effects of audio dimensionality on PX in VR. Results indicate that audio has a more implicit influence on PX in VR because of the impact of the overall sensory experience and that audio dimensionality in VR may not be a significant factor contributing to PX. Based on our findings and observations, we provide five design guidelines for VR games.

Year 2017

Evaluating VR Driving Simulation from a Player Experience Perspective

@inproceedings{10.1145/3027063.3053202,
author = {Walch, Marcel and Frommel, Julian and Rogers, Katja and Sch\"{u}ssel, Felix and Hock, Philipp and Dobbelstein, David and Weber, Michael},
title = {Evaluating VR Driving Simulation from a Player Experience Perspective},
year = {2017},
isbn = {9781450346566},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3027063.3053202},
doi = {10.1145/3027063.3053202},
abstract = {The majority of HCI research in the field of automotive interfaces and driver-vehicle interaction is conducted utilizing driving simulators. High-fidelity simulators are expensive; in consequence, many researchers use consumer gaming hardware and flat screens as an alternative. In recent years VR devices have become affordable and are applied already in some driving studies. It has not been shown whether driving simulations can use VR to increase immersion in low-cost setups. We conducted a pilot study with 20 participants using a racing game as simulation software. The results of this pilot study indicate that using a VR headset can potentially dissociate participants to a higher degree from the real world compared to the use of flat screens. However, participants felt a higher discomfort using the VR HMD. Despite expectations, today's VR technology does not appear to be a generally better choice than flat screens for driving simulator studies.},
booktitle = {Proceedings of the 2017 CHI Conference Extended Abstracts on Human Factors in Computing Systems},
pages = {2982–2989},
numpages = {8},
keywords = {driving simulation, simulator sickness, virtual reality, immersion, player experience, hmd},
location = {Denver, Colorado, USA},
series = {CHI EA '17}
}

The majority of HCI research in the field of automotive interfaces and driver-vehicle interaction is conducted utilizing driving simulators. High-fidelity simulators are expensive; in consequence, many researchers use consumer gaming hardware and flat screens as an alternative. In recent years VR devices have become affordable and are applied already in some driving studies. It has not been shown whether driving simulations can use VR to increase immersion in low-cost setups. We conducted a pilot study with 20 participants using a racing game as simulation software. The results of this pilot study indicate that using a VR headset can potentially dissociate participants to a higher degree from the real world compared to the use of flat screens. However, participants felt a higher discomfort using the VR HMD. Despite expectations, today's VR technology does not appear to be a generally better choice than flat screens for driving simulator studies.

Exploring the Potential of Game Audio for Wellbeing

@inproceedings{Rogers2017,
abstract = {Music listening has long-standing ties to mental health, positive affective states, and wellbeing. Even outside of clinical contexts, music is increasingly being explored as a costeffective, ubiquitous way to support emotion regulation and stress reduction in people's everyday lives. Games have also been shown to have the capability to improve player well-being in certain contexts. However, the role of players' exposure to background music in games toward leveraging this effect has not been explored specifically. We explore the potential of games to act as a tool for relaxation and stress reduction for the general public and discuss future research directions.},
address = {Amsterdam, Netherlands},
author = {Rogers, Katja and Nacke, Lennart E.},
booktitle = {Positive Gaming: Workshop on Gamification and Games for Wellbeing},
title = {{Exploring the Potential of Game Audio for Wellbeing}},
year = {2017}
}

Music listening has long-standing ties to mental health, positive affective states, and wellbeing. Even outside of clinical contexts, music is increasingly being explored as a costeffective, ubiquitous way to support emotion regulation and stress reduction in people’s everyday lives. Games have also been shown to have the capability to improve player well-being in certain contexts. However, the role of players’ exposure to background music in games toward leveraging this effect has not been explored specifically. We explore the potential of games to act as a tool for relaxation and stress reduction for the general public and discuss future research directions.

Exploring the Role of Audio in Games

@inproceedings{10.1145/3130859.3133227,
author = {Rogers, Katja},
title = {Exploring the Role of Audio in Games},
year = {2017},
isbn = {9781450351119},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3130859.3133227},
doi = {10.1145/3130859.3133227},
abstract = {Audio occurs in games in many forms and has the potential to significantly influence the player experience. My research explores immersive effects of audio design on components of the player experience. In particular, I analyze how the presence of different types of audio influences players' immersion, engagement and affective state. I plan to further explore this by comparing variations of specific audio types such as narrative and background music, for example versions with different affective associations. Further, I examine the role of audio within increasingly immersive virtual reality (VR) gaming technology. Through mixed-methods studies, I empirically explore how audio design influences the player experience in traditional and VR games. This dissertation research will contribute to understanding the role of audio within player-game interaction, by exploring the immersive effect of specific audio types and their variations. This will allow myself and the games research community to formulate recommendations for game designers and developers, and inform new research questions.},
booktitle = {Extended Abstracts Publication of the Annual Symposium on Computer-Human Interaction in Play},
pages = {727–731},
numpages = {5},
keywords = {narrative, virtual reality, immersion, audio, player experience, games},
location = {Amsterdam, The Netherlands},
series = {CHI PLAY '17 Extended Abstracts}
}

Audio occurs in games in many forms and has the potential to significantly influence the player experience. My research explores immersive effects of audio design on components of the player experience. In particular, I analyze how the presence of different types of audio influences players' immersion, engagement and affective state. I plan to further explore this by comparing variations of specific audio types such as narrative and background music, for example versions with different affective associations. Further, I examine the role of audio within increasingly immersive virtual reality (VR) gaming technology. Through mixed-methods studies, I empirically explore how audio design influences the player experience in traditional and VR games. This dissertation research will contribute to understanding the role of audio within player-game interaction, by exploring the immersive effect of specific audio types and their variations. This will allow myself and the games research community to formulate recommendations for game designers and developers, and inform new research questions.

LiverDefense: how to employ a tower defense game as a customisable research tool

@article{10.1007/s00371-016-1314-0,
author = {Brich, Julia and Rogers, Katja and Frommel, Julian and Weidhaas, Martin and Br\"{u}ckner, Adrian and Mirabile, Sarah and Dorn, Tamara and Riemer, Valentin and Schrader, Claudia and Weber, Michael},
title = {LiverDefense: How to Employ a Tower Defense Game as a Customisable Research Tool},
year = {2017},
issue_date = {April 2017},
publisher = {Springer-Verlag},
address = {Berlin, Heidelberg},
volume = {33},
number = {4},
issn = {0178-2789},
url = {https://doi.org/10.1007/s00371-016-1314-0},
doi = {10.1007/s00371-016-1314-0},
abstract = {In game-related research, it is often necessary to create different versions of a game prototype and gather information about players. To make this possible even for non-programmers, we present LiverDefense, an educational Tower Defense game about the basic functions of the human liver, which can be used as a customisable research tool. LiverDefense can be customised via human-readable XML files both in its degree of difficulty and the content of Likert scale questionnaires to be presented to the player. As a proof of concept, LiverDefense has been successfully employed in a psychological study focused on exploring the effect of perceived control over gameplay on players' emotions. We report on the analysis of this study with regard to enjoyment and frustration and the resulting insights on using LiverDefense as a customisable research tool.},
journal = {Vis. Comput.},
month = apr,
pages = {429–442},
numpages = {14},
keywords = {Game design, Bio-medical education, Educational games, Questionnaire integration, Customisable games}
}

In game-related research, it is often necessary to create different versions of a game prototype and gather information about players. To make this possible even for non-programmers, we present LiverDefense, an educational Tower Defense game about the basic functions of the human liver, which can be used as a customisable research tool. LiverDefense can be customised via human-readable XML files both in its degree of difficulty and the content of Likert scale questionnaires to be presented to the player. As a proof of concept, LiverDefense has been successfully employed in a psychological study focused on exploring the effect of perceived control over gameplay on players' emotions. We report on the analysis of this study with regard to enjoyment and frustration and the resulting insights on using LiverDefense as a customisable research tool.

Rising to the Challenge: An Emotion-Driven Approach Toward Adaptive Serious Games

@incollection{schrader2017rising,
  title={Rising to the challenge: An emotion-driven approach toward adaptive serious games},
  author={Schrader, Claudia and Brich, Julia and Frommel, Julian and Riemer, Valentin and Rogers, Katja},
  booktitle={Serious games and edutainment applications},
  pages={3--28},
  year={2017},
  publisher={Springer}
}

Serious games are steadily becoming a powerful tool for educational purposes as their challenging characteristics are suggested to make them particularly appealing to learn with. This challenging nature, however, comes at a price, namely, the need to maintain the optimal balance according to players’ emotional experiences. By focusing on players’ emotions as main player characteristic considered to be important for learning processes and performance, this chapter surveys empirical research and current game development that contributes to an emotion-adaptive framework for games. The goal of this chapter is to clarify the importance of continuously adjusting game characteristics to players’ emotional states. As the interaction between game characteristics and players’ emotions highlights the need for continuously assessing at what point gameplay becomes more or less positively or negatively affected, methods for emotion recognition are presented. A summary of adaptable game design elements as well as implementation methods for adaptivity are provided.

Year 2016

Bool the Miner: Relying on Ghost Companions to Solve Boolean Equations

@inproceedings{10.1145/2968120.2968122,
author = {Aufheimer, Maria and Bonenberger, Johannes and Klein, David and Kurashvili, Imin and Rogers, Katja},
title = {Bool the Miner: Relying on Ghost Companions to Solve Boolean Equations},
year = {2016},
isbn = {9781450344586},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/2968120.2968122},
doi = {10.1145/2968120.2968122},
abstract = {The game Bool the Miner is the result of a student project developed over two terms in a course on the design of serious games at Ulm University. Players direct the titular character Bool towards escaping from a mine. Each level represents a Boolean equation; the missing operations need to be inserted in switches to unlock the gate to the next level. Bool can record movement patterns for his helpful ghost companions, in order to operate multiple switches at the same time, while he completes an obstacle course towards the exit gate. As such, the game is a combination of the puzzle and jump'n'run genres. A pilot study investigated the validity of the game's approach towards practising knowledge of Boolean algebra, conducted alongside a psychological study on the effects of affective feedback as part of a multidisciplinary research project.},
booktitle = {Proceedings of the 2016 Annual Symposium on Computer-Human Interaction in Play Companion Extended Abstracts},
pages = {25–31},
numpages = {7},
keywords = {serious game, boolean algebra, jump'n'run, logic puzzle, movement playback, npc companions},
location = {Austin, Texas, USA},
series = {CHI PLAY Companion '16}
}

The game Bool the Miner is the result of a student project developed over two terms in a course on the design of serious games at Ulm University. Players direct the titular character Bool towards escaping from a mine. Each level represents a Boolean equation; the missing operations need to be inserted in switches to unlock the gate to the next level. Bool can record movement patterns for his helpful ghost companions, in order to operate multiple switches at the same time, while he completes an obstacle course towards the exit gate. As such, the game is a combination of the puzzle and jump'n'run genres. A pilot study investigated the validity of the game's approach towards practising knowledge of Boolean algebra, conducted alongside a psychological study on the effects of affective feedback as part of a multidisciplinary research project.

Towards Player-Centric Adaptivity: Interactions of Gameplay Behaviour and Player Traits in a Survival Game

@inproceedings{10.1145/2968120.2987725,
author = {Rogers, Katja and Kamm, Clemens and Weber, Michael},
title = {Towards Player-Centric Adaptivity: Interactions of Gameplay Behaviour and Player Traits in a Survival Game},
year = {2016},
isbn = {9781450344586},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/2968120.2987725},
doi = {10.1145/2968120.2987725},
abstract = {Feature-based player-centric game adaptivity offers many advantages in terms of optimising the player experience for wide appeal and replayability. Player typologies offer potential to steer adaptivity, as predicted by gameplay behaviour. However their applicability to the design of gameplay adaptation is yet to be fully explored. In this work, we investigate whether a trait-based typology correlates with player behaviour in a prototype survival game. We conducted an explorative study using BrainHex which showed no clear indication for the validity of this approach, raising questions for future research on player behaviour in games.},
booktitle = {Proceedings of the 2016 Annual Symposium on Computer-Human Interaction in Play Companion Extended Abstracts},
pages = {269–276},
numpages = {8},
keywords = {game adaptivity, player typology, survival genre, explorative study, brainhex},
location = {Austin, Texas, USA},
series = {CHI PLAY Companion '16}
}

Feature-based player-centric game adaptivity offers many advantages in terms of optimising the player experience for wide appeal and replayability. Player typologies offer potential to steer adaptivity, as predicted by gameplay behaviour. However their applicability to the design of gameplay adaptation is yet to be fully explored. In this work, we investigate whether a trait-based typology correlates with player behaviour in a prototype survival game. We conducted an explorative study using BrainHex which showed no clear indication for the validity of this approach, raising questions for future research on player behaviour in games.

Year 2015

Integrated Questionnaires: Maintaining Presence in Game Environments for Self-Reported Data Acquisition

@inproceedings{10.1145/2793107.2793130,
author = {Frommel, Julian and Rogers, Katja and Brich, Julia and Besserer, Daniel and Bradatsch, Leonard and Ortinau, Isabel and Schabenberger, Ramona and Riemer, Valentin and Schrader, Claudia and Weber, Michael},
title = {Integrated Questionnaires: Maintaining Presence in Game Environments for Self-Reported Data Acquisition},
year = {2015},
isbn = {9781450334662},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/2793107.2793130},
doi = {10.1145/2793107.2793130},
abstract = {Research in human-computer interaction often requires the acquisition of self-reported data. Particularly concerning serious games, the interaction between the game and the user still holds many unknown aspects, partly due to the user's double role as player and learner. An easy way of collecting data consists of questionnaires, mostly employed in pen-and-paper or electronic form. In order to gather data points during game play, the player is interrupted, potentially causing unintentional side effects. We suggest an integration of questionnaires into games as game elements, in order to mitigate the effects of interruption. A serious game prototype with an integrated survey was implemented, and evaluated regarding its effects on the players' experience of presence.},
booktitle = {Proceedings of the 2015 Annual Symposium on Computer-Human Interaction in Play},
pages = {359–368},
numpages = {10},
keywords = {self-reported data, immersion, player assessment, integrated questionnaires, serious games},
location = {London, United Kingdom},
series = {CHI PLAY '15}
}

Research in human-computer interaction often requires the acquisition of self-reported data. Particularly concerning serious games, the interaction between the game and the user still holds many unknown aspects, partly due to the user's double role as player and learner. An easy way of collecting data consists of questionnaires, mostly employed in pen-and-paper or electronic form. In order to gather data points during game play, the player is interrupted, potentially causing unintentional side effects. We suggest an integration of questionnaires into games as game elements, in order to mitigate the effects of interruption. A serious game prototype with an integrated survey was implemented, and evaluated regarding its effects on the players' experience of presence.

Mobile Augmented Reality as an Orientation Aid: A Scavenger Hunt Prototype

@inproceedings{10.1109/IE.2015.37,
author = {Rogers, Katja and Frommel, Julian and Breier, Larissa and Celik, Sinan and Kramer, Harry and Kreidel, Stefan and Brich, Julia and Riemer, Valentin and Schrader, Claudia},
title = {Mobile Augmented Reality as an Orientation Aid: A Scavenger Hunt Prototype},
year = {2015},
isbn = {9781467366540},
publisher = {IEEE Computer Society},
address = {USA},
url = {https://doi.org/10.1109/IE.2015.37},
doi = {10.1109/IE.2015.37},
abstract = {Orientation in public environments is a critical skill for new arrivals, yet also one that is usually only learned gradually through trial and error. This paper suggests the use of pervasive augmented reality (AR) for the design of a serious game that teaches navigational skills in a public environment. Many AR scavenger hunt games confront players with new environments by default, however they rarely focus explicitly on teaching navigational skills. We propose a concept that utilises augmented reality techniques for increased immersion and motivation, while upholding the real-world sense of presence for an easy transfer of orientation skills to everyday life. For this purpose, we implemented a first prototypical serious game in the form of an AR scavenger hunt. A preliminary evaluation regarding its usability produced promising results. As such, the prototype constitutes a first proof of concept. In future iterations, it will be further developed as an adaptive AR serious game, and evaluated in respect to its efficacy in teaching orientation and navigation skills.},
booktitle = {Proceedings of the 2015 International Conference on Intelligent Environments},
pages = {172–175},
numpages = {4},
series = {IE '15}
}

Orientation in public environments is a critical skill for new arrivals, yet also one that is usually only learned gradually through trial and error. This paper suggests the use of pervasive augmented reality (AR) for the design of a serious game that teaches navigational skills in a public environment. Many AR scavenger hunt games confront players with new environments by default, however they rarely focus explicitly on teaching navigational skills. We propose a concept that utilises augmented reality techniques for increased immersion and motivation, while upholding the real-world sense of presence for an easy transfer of orientation skills to everyday life. For this purpose, we implemented a first prototypical serious game in the form of an AR scavenger hunt. A preliminary evaluation regarding its usability produced promising results. As such, the prototype constitutes a first proof of concept. In future iterations, it will be further developed as an adaptive AR serious game, and evaluated in respect to its efficacy in teaching orientation and navigation skills.

Year 2014

P.I.A.N.O.: Faster Piano Learning with Interactive Projection

@inproceedings{10.1145/2669485.2669514,
author = {Rogers, Katja and R\"{o}hlig, Amrei and Weing, Matthias and Gugenheimer, Jan and K\"{o}nings, Bastian and Klepsch, Melina and Schaub, Florian and Rukzio, Enrico and Seufert, Tina and Weber, Michael},
title = {P.I.A.N.O.: Faster Piano Learning with Interactive Projection},
year = {2014},
isbn = {9781450325875},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/2669485.2669514},
doi = {10.1145/2669485.2669514},
abstract = {Learning to play the piano is a prolonged challenge for novices. It requires them to learn sheet music notation and its mapping to respective piano keys, together with articulation details. Smooth playing further requires correct finger postures. The result is a slow learning progress, often causing frustration and strain. To overcome these issues, we propose P.I.A.N.O., a piano learning system with interactive projection that facilitates a fast learning process. Note information in form of an enhanced piano roll notation is directly projected onto the instrument and allows mapping of notes to piano keys without prior sight-reading skills. Three learning modes support the natural learning process with live feedback and performance evaluation. We report the results of two user studies, which show that P.I.A.N.O. supports faster learning, requires significantly less cognitive load, provides better user experience, and increases perceived musical quality compared to sheet music notation and non-projected piano roll notation.},
booktitle = {Proceedings of the Ninth ACM International Conference on Interactive Tabletops and Surfaces},
pages = {149–158},
numpages = {10},
keywords = {camit, interactive projection, music, piano roll notation, instrument learning, muscial expression, piano},
location = {Dresden, Germany},
series = {ITS '14}
}

Learning to play the piano is a prolonged challenge for novices. It requires them to learn sheet music notation and its mapping to respective piano keys, together with articulation details. Smooth playing further requires correct finger postures. The result is a slow learning progress, often causing frustration and strain. To overcome these issues, we propose P.I.A.N.O., a piano learning system with interactive projection that facilitates a fast learning process. Note information in form of an enhanced piano roll notation is directly projected onto the instrument and allows mapping of notes to piano keys without prior sight-reading skills. Three learning modes support the natural learning process with live feedback and performance evaluation. We report the results of two user studies, which show that P.I.A.N.O. supports faster learning, requires significantly less cognitive load, provides better user experience, and increases perceived musical quality compared to sheet music notation and non-projected piano roll notation.