In the context of rising sedentary lifestyles, this paper investigates the efficacy of "Situated Artifacts"in promoting physical activity. We designed two artifacts that display users' physical activity data within their homes - one physical and one digital. We conducted a 9-week, counterbalanced, within-subject field study with N = 24 participants to assess the impact of these artifacts on physical activity, reflection, and motivation. We collected quantitative data on physical activity and administered daily and weekly questionnaires, employing individual Likert items and standardized instruments, as well as conducted interviews post-prototype usage. Our findings indicate that while both artifacts act as reminders for physical activity, the physical artifact was superior in terms of user engagement. The study revealed that this can be attributed to the higher perceived presence and, thereby, enhanced social interaction, which acts as a motivational source for activity. In this sense, situated artifacts gently nudge toward sustainable health behavior change.

Electrical Muscle Stimulation (EMS) has unique capabilities that can manipulate users’ actions or perceptions, such as actuating user movement while walking, changing the perceived texture of food, and guiding movements for a user learning an instrument. These applications highlight the potential utility of EMS, but such benefits may be lost if users reject EMS. To investigate user acceptance of EMS, we conducted an online survey (N = 101). We compared eight scenarios, six from HCI research applications and two from the sports and health domain. To gain further insights, we conducted in-depth interviews with a subset of the survey respondents (N = 10). The results point to the challenges and potential of EMS regarding social and technological acceptance, showing that there is greater acceptance of applications that manipulate action than those that manipulate perception. The interviews revealed safety concerns and user expectations for the design and functionality of future EMS applications.

The global COVID-19 pandemic created a constant need for hand disinfection. While it is still essential, disinfection use is declining with the decrease in perceived personal risk (e.g., as a result of vaccination). Thus this work explores using different visual cues to act as reminders for hand disinfection. We investigated different public display designs using (1) paper-based only, adding (2) screen-based, or (3) projection-based visual cues. To gain insights into these designs, we conducted semi-structured interviews with passersby (N=30). Our results show that the screen- and projection-based conditions were perceived as more engaging. Furthermore, we conclude that the disinfection process consists of four steps that can be supported: drawing attention to the disinfection station, supporting the (subconscious) understanding of the interaction, motivating hand disinfection, and performing the action itself. We conclude with design implications for technology-supported disinfection.

The last decade has witnessed an increase in Electrical Muscle Stimulation (EMS) research. Myriads of application scenarios have been proposed and toolkits, as well as procedures, have been presented to the research community. While these individual explorations provide a benefit to the research community, the overarching view on the topic is still unclear which helps to understand how such technology can be used in the future. To tackle this, we conduct a systematic literature survey of research utilizing EMS as a wearable output method. We investigate the published research (N = 151) by analyzing the EMS systems’ setup, calibration, and evaluation. We create a taxonomy of the application scenarios that categorize them along two dimensions (i.e., (1) action <> perception and (2) augmentation <> induction). Further, we distill open research challenges from our results that can help to stimulate and guide research on EMS in the future.

Displays are a ubiquitous part of our everyday life. Digital, as well as paper-based displays, are used on various occasions to present us with different information. While users cannot interact with many of these displays yet, they could benefit from making them interactive. Research shows that thermal cameras can be exploited to make surfaces interactive by sensing touchpoints based on the heat signature and residue. However, most of the research done uses a stationary setup. This work proposes HeatGoggles, a wearable gadget detecting touch input on arbitrary surfaces using thermal imaging. We report on its design, prototypical implementation, and first evaluation. We show that it can be used on non-touch-enabled displays as well as other traditional information displays.

Racket sports offer an enjoyable form of physical activity and are fertile ground for interactive technologies supporting new players. Yet, current research has neglected its potential to support not only active players but also coaches in their training methods. To investigate how interactive technologies can support skill acquisition in training, we designed an Electrical Muscle Stimulation (EMS) system that helps maintain the ready position in crossminton. We compared the system with a vibrotactile solution in a user study, interviewing novice players and experienced coaches about their perception of the system. The system allowed coaches to effectively and immediately guide players to the ready position. An EMS-based feedback system for coaches can potentially reduce delay (physical and cognitive) for trainees, as stated by coaches. Our work contributes insights into designing systems that facilitate learning sports techniques using interactive feedback.

Over recent decades, with the fast growth of urbanization, new health-related issues have resulted from the changed lifestyles. People have become more sedentary. They suffer from fully-packed calendars, which does not give them enough time to care for their physical and psychological well-being. While this is a growing challenge, advancements made in internet of things (IoT) devices in the private context offer the chance to develop applications that tackle these issues. While many such applications have been envisioned, the user’s views and requirements for them remain unclear. To better understand this, we conducted a literature review in which we identified the four most common health-related scenarios in which such technologies are used. Next, we conducted an online survey (N=80), in which participants envisioned how smart home devices could realize these scenarios. Based on the results, we derive design implications that show that users value a high degree of customization and the ability to select a specific automation level through an all-in-one, easy-to-use platform.

Automated vehicles (AVs) are on the edge of being available on the mass market. Research often focuses on technical aspects of automation, such as computer vision, sensing, or artificial intelligence. Nevertheless, researchers also identified several challenges from a human perspective that need to be considered for a successful introduction of these technologies. In this paper, we first analyze human needs and system acceptance in the context of AVs. Then, based on a literature review, we provide a summary of current research on in-car driver-vehicle interaction and related human factor issues. This work helps researchers, designers, and practitioners to get an overview of the current state of the art.

One of the main benefits of interactive Virtual Reality (VR) applications is that they provide a high sense of immersion. As a result, users lose their sense of real-world space which makes them vulnerable to collisions with real-world objects. In this work, we propose a novel approach to prevent such collisions using Electrical Muscle Stimulation (EMS). EMS actively prevents the movement that would result in a collision by actuating the antagonist muscle. We report on a user study comparing our approach to the commonly used feedback modalities: audio, visual, and vibro-tactile. Our results show that EMS is a promising modality for restraining user movement and, at the same time, rated best in terms of user experience.

Human computer interaction models deliver a conceptual overview of the fundamental communication processes between the computer and the human. The aim of these models is to provide an easy understanding of a system’s behaviour on a meta level. Existing HCI models cover most of the actual interaction modalities. New arising technologies provide the possibility of directly manipulating the human action – called actuation. Such interaction, however, is not covered by classical models. In this work, we propose additional relations extending current HCI models to include novel interactions using human actuation.

The uprising levels of autonomous vehicles allow the drivers to shift their attention to non-driving tasks while driving (i.e., texting, reading, or watching movies). However, these systems are prone to failure and, thus, depending on human intervention becomes crucial in critical situations. In this work, we propose using human actuation as a new mean of communicating take-over requests (TOR) through proprioception. We conducted a user study via a driving simulation in the presence of a complex working memory span task. We communicated TORs through four different modalities, namely, vibrotactile, audio, visual, and proprioception. Our results show that the vibrotactile condition yielded the fastest reaction time followed by proprioception. Additionally, proprioceptive cues resulted in the second best performance of the non-driving task following auditory cues.

Currently offered autonomous vehicles still require the human intervention. For instance, when the system fails to perform as expected or adapts to unanticipated situations. Given that reliability of autonomous systems can fluctuate across conditions, this work is a first step towards understanding how this information ought to be communicated to users. We conducted a user study to investigate the effect of communicating the system's reliability through a feedback bar. Subjective feedback was solicited from participants with questionnaires and semi-structured interviews. Based on the qualitative results, we derived guidelines that serve as a foundation for the design of how autonomous systems could provide continuous feedback on their reliability.

Cooking has the potential to bring joy, a sense of achievement and social presence to individuals and groups. Food properties (food cues) such as scent, sound and taste are rich cues to the state of the cooking process, as well as, providing memories evoking emotions attached to social situations and people from the past. Thus, optimal methods to capture and present these cues is an on-going research challenge. In this workshop, we bring researchers, amateur cooks, and designers together to explore two research questions:1) how does enhancing our awareness of food temperature support a joyful and/or a memorable cooking experience? and 2) how can we use food cues to enhance our sense of joy, empower reminiscence and nudge communication between individuals?. We aim through this event to foster a research community that uses food interaction as a medium to promote a sense of joyfulness and social wellbeing.

With the expansion of multicultural communities, raising awareness to diminish cultural misconceptions became a must. We investigate different research probes using interactive Virtual Reality (VR) applications to increase such awareness. VR environments provide a high sense of immersion, which enhance the user's experience. In this work, we present three VR interactive research probes that allow users to understand cultural differences and to reduce cultural misconceptions.