Abstract Voice-based interaction is experiencing a second wind through the advent of machine learning (ML) techniques, affordable consumer products and renewed work on natural language processing (NLP) and large language models (LLMs). A growing body of work is exploring how users perceive new forms of computer-generated voices from qualitative and quantitative angles. However, critical voices have called for greater rigour, especially in confirming the voice as a manipulated variable, i.e. manipulation checks. We present three case studies that highlight the value of investing in rigorous manipulation checks for HCI researchers and designers. We demonstrate the importance of testing assumptions, the need for care and reflection in the design of response options and measurement and the advantages of more exploratory approaches to understanding user perceptions of and user experiences (UX) with voice phenomena. Through these case studies, we raise awareness, empirically justify and critically assess the value of manipulation checks for voice UX research and beyond.

Abstract Formalized literature reviews are crucial in human–computer interaction (HCI) because they synthesize research and identify unsolved problems. However, current practices lack transparency when reporting details of a literature search. This restricts replicability. This paper introduces the INSPIRE framework for HCI research. It focuses on the search stage in literature reviews to support a search that prioritizes transparency and quality-of-fit to a research question. It was developed based on guiding principles for successful searches and precautions advised by librarian experts in HCI (n=8) for search strategies in (primarily systematic) literature reviews. We discuss how their advice aligns with the HCI field and their concerns about computational AI tools assisting or automating these reviews. Based on their advice, the framework outlines pivotal stages in conducting a literature search. These essential stages are: (1) defining research goals, (2) navigating relevant databases and (3) using searching techniques (like divergent and convergent searching) to identify a set of relevant studies. The framework also emphasizes the importance of team involvement, transparent reporting, and a flexible, iterative approach to refining the search terms.

Built environments increasingly incorporate new forms of intelligence, creating opportunities for enhancing human interactive experiences with and within building spaces.This scoping review examines design interventions and discourses within the domain of "Smart Buildings".The goal is to identify and characterise the type of human experiences that research in this domain aims to address.Using a hybrid deductive-inductive coding approach, we analysed 192 papers related to human experiences and smart buildings from ACM Digital Library and Scopus published between 1996 and 2024.Our analysis revealed 11 distinct "targeted human experiences", 20 commonly used "design mechanisms" to achieve those design goals, as well as two typologies of "technological interventions".Our findings create a foundation for understanding building design research and the range of human experience they entail.

Sedentary occupations and recreational activities carried out primarily while seated promote extended time periods spent in unhealthy sitting postures, contributing to physical and mental health issues. While apps and reminders can be effective, they often fail to sustain enjoyment and motivation or do not target stationary settings. In our work, we investigate whether sedentary waiting periods could be broken up through gentle full-body movements via full-body interactions on a large touchwall instead of remaining seated or standing. In a mixed-methods study (N=18), we compared a Match-3 game played (1) on a full-body touchwall, (2) on a smartphone standing, and (3) on a smartphone sitting, investigating user experience, performance, and acceptance. The touchwall game subtly motivated people to move, stretch and bend their bodies without performance loss while enjoying the game compared to the smartphone conditions. We suggest that full-body touchwall interaction has the potential to fill occasional waiting time while encouraging breaking up sedentary behavior.

While juiciness in games has previously been explored in the context of visual embellishments, less is known about whether and how the concept is leveraged in the context of audio and sound design. In our work, we address this issue through in-depth interviews with twelve audio designers working in the games industry. Through thematic analysis and content analysis, we show that principles of juicy design also apply to audio and sound design, and that it is applied intentionally to improve player feedback and experience. On this basis, our work contributes a conceptual foundation for juicy audio in its key factors of emphasis/augmentation, cohesion/coherence, and synesthesia. We identify associated attributes and provide implications for the design of games that seek to leverage juicy audio as a means of improving player experience.

In gamification users show increased motivation and engagement towards tasks. So far, this effect has mostly been empirically tested based on the visual depiction of game elements, while research on the use and addition of auditory aspects is sparse. In this work we investigate the effect of different modalities of game elements (auditory, visual, audiovisual) on user experience, perception and performance in a gamified image-tagging task. We approached this via an online validation survey to find suitable sound effects (N=50), a main quantitative study (N=109) and a qualitative semi-structured interview (N=9). Our results show that while visual gamification increases performance, auditory and audiovisual gamification had no effect. However, they were shown to have an influence on the user's flow state. Our qualitative follow-up study shed light on underlying reasons and revealed each modality has its own drawbacks and advantages and that combining both visual and auditory aspects was preferred by participants.

Toxic behavior is known to cause harm in online games. Players regularly experience negative, hateful, or inappropriate behavior. Interventions, such as banning players or chat message filtering, can help combat toxicity but are not widely available or even comprehensively studied regarding their approaches and evaluations. We conducted a systematic literature review that provides insights into the current state of interventions literature, outlining their strengths and shortcomings. We identified 36 interventions and qualitatively analyzed their approaches. We describe the types of toxicity being addressed, the entities through which they act, the methods used by intervention systems, and how they are evaluated. Our results provide guidance for future interventions, outlining a design space based on known systems. Furthermore, our findings highlight gaps in the literature, e.g., a sparsity of empirical evaluations, and underexplored areas in the design space, enabling researchers to explore novel directions for future interventions.

Systematic reviews (SRs) are vital to gathering and structuring knowledge, yet descriptions of their procedures are often inadequate. In human–computer interaction (HCI), SRs are still uncommon but gaining momentum, which prompted us to explore how SRs are reported at CHI—the flagship HCI conference venue. To assess the reporting quality of CHI reviews that aim for a systematic approach, we conducted an umbrella review and applied reporting guidelines for SRs (PRISMA and ENTREQ) to our corpus. We contribute the first exploration of how well SRs at CHI meet guidelines for reporting quality, showcasing strategies for improvement in reporting and conducting SRs especially in the domains of appraisal, synthesis, and documentation (i.e., protocol development). Finally, we present guiding questions for HCI researchers and practitioners for reporting SRs, as well as suggestions for best practices.

Game economies (GEs) describe how resources in games are created, transformed, or exchanged: They underpin most games and exist in different complexities. Their complexity may directly impact player difficulty. Nevertheless, neither difficulty nor complexity adjustment has been explored for GEs. Moreover, there is a lack of knowledge about complexity in GEs, how to define or assess it, and how it can be employed by automated adjustment approaches in game development to target specific complexity. We present a proof-of-concept for using evolutionary algorithms to craft targeted complexity graphs to model GEs. In a technical evaluation, we tested our first working definition of complexity in GEs. We then evaluated player-perceived complexity in a city-building game prototype through a user study and confirmed the generated GEs' complexity in an online survey. Our approach toward reliably creating GEs of specific complexity can facilitate game development and player testing but also inform and ground research on player perception of GE complexity.

Sound effects (SFX) complement the visual feedback provided by gamification elements in gamified systems. However, the impact of SFX has not been systematically studied. To bridge this gap, we investigate the effects of SFX—supplementing points (as a gamification element)—on task performance and user experience in a gamified image classification task. We created 18 SFX, studied their impact on perceived valence and arousal (N = 49) and selected four suitable SFX to be used in a between-participants user study (N = 317). Our findings show that neither task performance, affect, immersion, nor enjoyment were significantly affected by the sounds. Only the pressure/tension factor differed significantly, indicating that low valence sounds should be avoided to accompany point rewards. Overall, our results suggest that SFX seem to have less impact than expected in gamified systems. Hence, using SFX in gamification should be a more informed choice and should receive more attention in gamification research.

In interactive story games, players make decisions that advance and modify the unfolding story. In many cases, these decisions have a moral component. Examining decision-making in these games illuminates whether players mobilize their real-life morality to make in-game decisions and what impact this has in both the game world and real life. Using mixed-methods consisting of semi-structured interviews and the Moral Foundations Questionnaire (MFQ30), we collected data from 19 participants who played the game Detroit: Become Human. We analyzed how participants applied their real-life morals toward in-game decisions using thematic analysis and statistical analysis of the MFQ30 results. Qualitative findings indicate that participants mobilize their moral intuitions to make in-game decisions and how much participants cared about their game characters influenced their choices. We contribute a better understanding of how players react to moral dilemmas in interactive story games for game designers to help them improve player experience.

Researchers reference realism in digital games without sufficient specificity. Without clarity about the dimensions of realism, we cannot assess how and when to aim for a higher degree of realism, when lower realism suffices, or when purposeful unrealism is ideal for a game and can benefit player experience (PX). To address this conceptual gap, we conducted a systematic review using thematic synthesis to distinguish between types of realism currently found in the digital games literature. We contribute qualitative themes that showcase contradictory design goals of realism/unrealism. From these themes, we created a framework (i.e., a hierarchical taxonomy and mapping) of realism dimensions in digital games as a conceptual foundation. Our themes and framework enable a workable specificity for designing or analyzing types of realism, equip future work to explore effects of specific realism types on PX, and offer a starting point for similar efforts in non-game applications.

Visual indicators provide important in-game information, but displaying them on screen consumes space and increases clutter. In addition, the option to increase indicator brightness above levels possible in standard monitors can substantially improve accessibility. To address both aspects, we developed an ambient lighting system for video game indicators using an LED strip attached around the back border of a monitor. A controlled study compares the speed, error rate, and perceived workload of this approach with an on-screen baseline method. Results show that ambient lights can capture attention 17.5% faster compared to on-screen indicators, and ambient lights performed at least as well as on-screen across all other metrics. Our work provides empirical evidence that ambient lights can be an adequate replacement for on-screen methods when displaying indicators in games, allowing people to reclaim screen real estate and adjust brightness for accessibility, without sacrificing performance.

Team cohesion is a widely known predictor of performance and collaborative satisfaction. However, how it develops and can be assessed, especially in fast-paced ad hoc dynamic teams, remains unclear. An unobtrusive and objective behavioural measure of cohesion would help identify determinants of cohesion in these teams. We investigated team communication as a potential measure in a mixed-methods study with 48 teams (n=135) in the digital game League of Legends. We first established that cohesion shows similar performance and satisfaction in League of Legends. teams as in non-game teams and confirmed a positive relationship between communication word frequency and cohesion. Further, we conducted an in-depth exploratory qualitative analysis of the communication sequences in a high-cohesion and a low-cohesion team. High cohesion is associated with sequences of apology->encouragement, suggestion->agree/acknowledge, answer->answer, and answer->question, while low-cohesion is associated with sequences of opinion/analysis->opinion/analysis, disagree->disagree, command->disagree, and frustration->frustration. Our findings also show that cohesion is important to team satisfaction independently of the match outcomes. We highlight that communication sequences are more useful than frequencies to determine team cohesion via player interactions.

Virtual reality (VR) multiplayer games increasingly use asymmetry (e.g., differences in a person’s capability or the user interface) and resulting interdependence between players to create engagement even when one player has no access to a head-mounted display (HMD). Previous work shows this enhances player experience (PX). Until now, it remains unclear whether and how an asymmetric game design with interdependences creates comparably enjoyable PX for both an HMD and a non-HMD player. In this work, we designed and implemented an asymmetric VR game (different in its user interface) with two types of interdependence: strategic (difference in game information/player capability) and biometric (difference in player’s biometric influence). Our mixed-methods user study (N=30) shows that asymmetries positively impact PX for both player roles, that interdependence strongly affects players’ perception of agency, and that biometric feedback—while subjective—is a valuable game mechanic.

The design space of social exergames remains narrow despite the many benefits of playing and exercising together. Towards opening this design space, we followed a Research through Design (RtD) approach focused on exergames that can be fun and immersive social training experiences. Through embodied sketching activities with designers and 10 pairs of players, we explored future games for the ExerCube, an immersive exergame platform. Our work contributes with forms of intermediate-level knowledge: a design space model (the Immersive Social Fitness—ImSoFit—Games model); and a novel design vocabulary including new bodily orientations in co-located physical interaction. We illustrate their use and value scrutinizing three of our games and applying three analytical lenses to 1) understand how design choices impact how players move together; 2) evaluate design expectations and analyze players’ behavior in relation to design choices; and 3) potentially extend the design space of immersive co-located social fitness games.

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.

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.

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.

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.

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.

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.