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.

There seems to be a solid object inside.""What other toppings do you usually like on your pizza?" Figure 1: We imbued a robot with curious behaviors.The figure shows two examples.Left: The robot shakes a container to check whether there is an object inside.Right: The robot asks for the person's preferences.

Human-centered security research traditionally leverages self-reports and high-level behavioral data. However, the increasing ubiquity of sensors integrated into personal, wearable devices (e.g., smartphones, smartwatches) and in users’ environments (e.g., cameras) enables researchers to unobtrusively collect rich physiological and behavioral signals. These real-time data streams can reveal user states—such as attention or workload—that can be employed to design adaptive security mechanisms. In this paper, we present a platform that supports designing, building, and evaluating next-generation user interfaces that leverage physiological and behavioral data for enhanced security. First, we introduce the physio-behavioral security paradigm, highlighting how sensor-based insights into user states can inform individualized security interventions and accurately identify moments of vulnerability. We then outline the requirements, system architecture, and implementation details of the platform, illustrating how multiple data streams (e.g., gaze, heart rate, keystrokes, mouse movements) are integrated and securely processed. Finally, we report on an exploratory deployment in a mid-sized organization, showcasing how the tool captures real-time security behaviors and enables context-aware interventions. The deployment yields insights into factors influencing acceptance across different stakeholders (management, IT department, employees). Our results suggest that adaptive approaches, informed by physiological and behavioral signals, can improve security outcomes and user acceptance.

Smartphone overuse is hyper-prevalent in society, and developing tools to prevent this overuse has become a focus of HCI. However, there is a lack of work investigating smartphone overuse interventions over the long term. We collected usage data from N = 1, 039 users of one sec over an average of 13.4 weeks and qualitative insights from 249 of the users through an online survey. We found that users overwhelmingly choose to target Social Media apps. We found that the short design frictions introduced by one sec effectively reduce how often users attempt to open target apps and lead to more intentional app-openings over time. Additionally, we found that users take periodic breaks from one sec interventions, and quickly rebound from a pattern of overuse when returning from breaks. Overall, we contribute findings from a longitudinal investigation of design frictions in the wild and identify usage patterns from real users in practice.

Social interaction is a crucial part of what it means to be human. Maintaining a healthy social life is strongly tied to positive outcomes for both physical and mental health. While we use personal informatics data to reflect on many aspects of our lives, technology-supported reflection for social interactions is currently under-explored. To address this, we first conducted an online survey (N=124) to understand how users want to be supported in their social interactions. Based on this, we designed and developed an app for users to track and reflect on their social interactions and deployed it in the wild for two weeks (N=25). Our results show that users are interested in tracking meaningful in-person interactions that are currently untraced and that an app can effectively support self-reflection on social interaction frequency and social load. We contribute insights and concrete design recommendations for technology-supported reflection for social interaction.

This paper explores (1) the role of metaphors in physical data representations and (2) the concept of tacit data: implicitly known data which are hard to uncover. In a semester course with twenty-three students, five teams explored how to represent self-chosen ‘tacit data’ in a visualisation, haptification, and dynamic physicalisation. Throughout these phases, our notion of tacit data evolved, resulting in a proposed working definition. Moreover, we noticed that metaphors played an increasingly important role. Based on analysis of students’ work and interviews with them, we found that tacit data and physical data representations need metaphors. For haptifications and physicalisations, metaphors help to circumvent limitations, curate data, and communicate to the audience. As tacit data were seen as ‘soft’ and difficult to quantify, metaphors made the data workable. Furthermore, tacit data benefit from physical representations, which offer further dimensions to represent the feeling and intimate aspects of data.

Social media platforms use short, highly engaging videos to catch users’ attention. While the short-form video feeds popularized by TikTok are rapidly spreading to other platforms, we do not yet understand their impact on cognitive functions. We conducted a between-subjects experiment (N = 60) investigating the impact of engaging with TikTok, Twitter, and YouTube while performing a Prospective Memory task (i.e., executing a previously planned action). The study required participants to remember intentions over interruptions. We found that the TikTok condition significantly degraded the users’ performance in this task. As none of the other conditions (Twitter, YouTube, no activity) had a similar effect, our results indicate that the combination of short videos and rapid context-switching impairs intention recall and execution. We contribute a quantified understanding of the effect of social media feed format on Prospective Memory and outline consequences for media technology designers to not harm the users’ memory and wellbeing.

While walking meetings offer a healthy alternative to sit-down meetings, they also pose practical challenges. Taking notes is difficult while walking, which limits the potential of walking meetings. To address this, we designed the Walking Talking Stick—a tangible device with integrated voice recording, transcription, and a physical highlighting button to facilitate note-taking during walking meetings. We investigated our system in a three-condition between-subjects user study with thirty pairs of participants (N=60) who conducted 15-minute outdoor walking meetings. Participants either used clip-on microphones, the prototype without the button, or the prototype with the highlighting button. We found that the tangible device increased task focus, and the physical highlighting button facilitated turn-taking and resulted in more useful notes. Our work demonstrates how interactive artifacts can incentivize users to hold meetings in motion and enhance conversation dynamics. We contribute insights for future systems which support conducting work tasks in mobile environments.

Communication is crucial for interpersonal connection, but sometimes we simply cannot find the right words. Some data, such as complex emotions, are either hard to quantify or are otherwise difficult to communicate. We have access to numerous personal statistics from quantified self devices, but hidden data are either untracked or require abstraction. In this paper, we explore physicalizations to communicate hidden data between couples. We recruited six couples (N=12 participants, 163 telegram responses) to participate in a two-week sensitization diary study followed by two participatory co-design sessions. We then hosted a one-day expert prototyping workshop (N=5) to create tangible artifacts based on the findings of the participatory phase. By iterating on the topic in three ways, we contribute (i) a design framework for understanding and tangibly representing hidden data, (ii) a discussion on the appropriateness of these methodologies, and (iii) open research questions to guide future research in the field.

Exploring the great outdoors offers physical and mental health benefits. Hiking is healthy, provides a sense of accomplishment, and offers an opportunity to relax. However, a nature trip is not always possible, and there is a lack of evidence showing how these beneficial experiences can be replicated in Virtual Reality (VR). In response, we recruited (N=24) participants to explore a virtual mountain landscape in a within-subjects study with different levels of exertion: walking, using a chairlift, and teleporting. We found that physical exertion when walking produced significantly more positive emotions and mindfulness than other conditions. Our research shows that physically demanding outdoor activities in VR can be beneficial for the user and that the achievement of hiking up a virtual mountain on a treadmill positively impacts wellbeing. We demonstrate how physical exertion can be used to add mindfulness and positive affect to VR experiences and discuss consequences for VR designers.

We present MindPhone, a mindfulness-based intervention to tackle absentminded and excessive smartphone use. At unlock, MindPhone prompts one of two questions: what the user intends to do with the smartphone, or what the user intends to do in the real world after using their smartphone. Users may respond actively by writing, or passively by mentally reflecting. We evaluated the effectiveness of the two questions and two response modes in a mixed-method, 2x2 mixed field study with 28 participants over two weeks. Our results show that the real-world prompt significantly reduces absentminded use and encourages a quicker return to the real world, independent of the response mode. Asking about smartphone use intentions raises awareness of reasons for smartphone use. For everyday use of MindPhone, users wish to set the question and response mode based on context. We discuss including awareness of the physical world in future smartphone use interventions.

Absent-minded smartphone use has become a catalyst for digital stress. It is often triggered by the mere presence of the device itself, inciting physical opt-out solutions with potentially severe drawbacks. Consequently, there is a need to explore the design dimensions and entailing limitations of physical opt-out methods, especially for everyday use. Informed through expert interviews and online questionnaires, we designed a proof of concept prototype that creates a physical barrier between users and their smartphones while maintaining ease of access. We evaluated our prototype concept in a two-week in-the-wild study, surfacing known benefits of physical opt-out strategies, such as encouraging reflection and supporting deliberate breaks. Although we reduced absent-minded use for users with a high predisposition, drawbacks such as Fear of Missing Out (FoMO) remain. Our work highlights that finding the appropriate amount of physical separation is essential when designing opt-out strategies for digital wellbeing.

Traditional meetings involve extensive sitting, which negatively impacts the health of attendees. Understanding how technology can facilitate integrating physical activity into the workplace, such as in walking meetings, is vital to improving workplace wellbeing. To that end, we applied a mixed-method approach to explore requirements and opportunities for walking meetings. We conducted an online questionnaire and a series of interviews with early adopters of walking meetings and created design fictions based on their feedback. We evaluated the design fictions with a second questionnaire and garnered additional feedback from the original early adopters. Based on our findings, we derived four dimensions associated with walking meetings: practical, environmental, social, and cognitive facets. We define attributes, challenges, and opportunities within these dimensions which are important for designing systems that support walking meetings. Our work identifies key considerations for developing systems that integrate physical activity into communication activities.