In-person, Online and Back Again - A Tale of Three Hybrid HackathonsHybrid hackathons, which combine in-person and online participation, present unique challenges for organizers and participants. Although these events are increasingly conducted globally, research on them remains fragmented, with limited integration between hackathon studies and hybrid collaboration. Existing strategies for in-person or online-only events often fail to address the unique challenges of hybrid formats, such as managing communication across physical and virtual spaces and ensuring balanced participation. Our work addresses this gap by examining how hybrid hackathons function through the lens of hybrid collaboration theories, analyzing how organizers structure these events and how participants navigate hybrid-specific challenges. Drawing on established theories of hybrid collaboration, we examine key dimensions -- synchronicity, physical distribution, dynamic transitions, and technological infrastructure -- that shape collaboration in hybrid events. Through an exploratory case study of three hackathon events involving observations and interviews with organizers and participants, we analyze how these dimensions are implemented and their effects on participant experiences. Our findings reveal differing organizer considerations of the hybrid dimensions in the hackathon design, leading to distinct experiences for participants. Implementation styles -- favoring in-person, online, or balanced participation -- led to varied participant experiences, affecting access to resources, communication, and team coordination. Organizers in our study also often relied on technology to bridge hybrid interactions, but sometimes overlooked critical aspects like time-zone management, dynamic transitions, and targeted support for hybrid teams. Additionally, participants in their teams responded to gaps in event scaffolding by adapting collaboration strategies, underscoring that hybrid formats are still not fully integrated into hackathon planning and revealing gaps in organizers’ preparedness for hybrid events. Learning from our findings, we offer practical recommendations when organizing hybrid hackathon events and recommendations to participants when attending hybrid hackathon events.2025AAAbasi-Amefon Obot Affia et al.Hybrid WorkCSCW
SoniWeight Shoes: Investigating Effects and Personalization of a Wearable Sound Device for Altering Body Perception, Behavior and Emotion Changes in body perception influence behavior and emotion and can be induced through multisensory feedback. Auditory feedback to one's actions can trigger such alterations; however, it is unclear which individual factors modulate these effects. We employ and evaluate SoniWeight Shoes, a wearable device based on literature for altering one's weight perception through manipulated footstep sounds. In a healthy population sample across a spectrum of individuals (n=84) with varying degrees of eating disorder symptomatology, physical activity levels, body concerns, and mental imagery capacities, we explore the effects of three sound conditions (low-frequency, high-frequency and control) on extensive body perception measures (demographic, behavioral, physiological, psychological, and subjective). Analyses revealed an impact of individual differences in each of these dimensions. Besides replicating previous findings, we reveal and highlight the role of individual differences in body perception, offering avenues for personalized sonification strategies. Datasets, technical refinements, and novel body map quantification tools are provided.2024ADAmar D'Adamo et al.Universidad Carlos III de MadridVibrotactile Feedback & Skin StimulationFull-Body Interaction & Embodied InputFoot & Wrist InteractionCHI
Explaining It Your Way - Findings from a Co-Creative Design Workshop on Designing XAI Applications with AI End-Users from the Public SectorHuman-Centered AI prioritizes end-users' needs like transparency and usability. This is vital for applications that affect people's everyday lives, such as social assessment tasks in the public sector. This paper discusses our pioneering effort to involve public sector AI users in XAI application design through a co-creative workshop with unemployment consultants from Estonia. The workshop's objectives were identifying user needs and creating novel XAI interfaces for the used AI system. As a result of our user-centered design approach, consultants were able to develop AI interface prototypes that would support them in creating success stories for their clients by getting detailed feedback and suggestions. We present a discussion on the value of co-creative design methods with end-users working in the public sector to improve AI application design and provide a summary of recommendations for practitioners and researchers working on AI systems in the public sector.2024KWKatharina Weitz et al.University of AugsburgExplainable AI (XAI)Participatory DesignCHI
Lost in the Deep? Performance Evaluation of Dead Reckoning Techniques in Underwater Environments"Computing research is increasingly addressing underwater environments and examining how computing can support diving and other activities. Unlike on land, where well-established positioning methods are widely available, underwater environments lack a common positioning mechanism, which is a prerequisite for many applications. Dead reckoning, the use of angle and distance estimates to track position changes from a known point of origin, is a promising candidate for underwater positioning as it does not rely on wireless signals (which decay rapidly in underwater environments) and as there is a wide range of literature and algorithms freely available. Yet, currently it is unclear whether the existing techniques can be adopted in underwater environments or whether the differences in medium and environment affect the performance of the dead reckoning techniques. We contribute by evaluating and systematically analyzing the performance and trade-offs associated with dead reckoning techniques in underwater environments. We present AEOLUS, a prototype unit comprising of a low-cost microcontroller and inertial measurement unit, to perform experiments on the ground and in underwater environments to assess how well the performance of different techniques translates from ground-based use cases to underwater environments. We benchmark 15 different algorithms and compare their performance in such environments to identify common patterns and dissimilarities, and identify root causes for these differences. The results show that displacement and turn errors can be estimated to within 5% error but that the best performing methods vary between land and underwater environments. We also show that the performance depends on the shape of the motion patterns with some algorithms performing better for hard turns whereas others perform better for gradual, more continuous turns. https://dl.acm.org/doi/10.1145/3596245"2023MRMARKO RADETA et al.Context-Aware ComputingUbiquitous ComputingUbiComp
HIPPO: Persuasive Hand-Grip Estimation from Everyday InteractionsHand-grip strength is widely used to estimate muscle strength and it serves as a general indicator of the overall health of a person, particularly in aging adults. Hand-grip strength is typically estimated using dynamometers or specialized force resistant pressure sensors embedded onto objects. Both of these solutions require the user to interact with a dedicated measurement device which unnecessarily restricts the contexts where estimates are acquired. We contribute HIPPO, a novel non-intrusive and opportunistic method for estimating hand-grip strength from everyday interactions with objects. HIPPO re-purposes light sensors available in wearables (e.g., rings or gloves) to capture changes in light reflectivity when people interact with objects. This allows HIPPO to non-intrusively piggyback everyday interactions for health information without affecting the user's everyday routines. We present two prototypes integrating HIPPO, an early smart glove proof-of-concept, and a further optimized solution that uses sensors integrated onto a ring. We validate HIPPO through extensive experiments and compare HIPPO against three baselines, including a clinical dynamometer. Our results show that HIPPO operates robustly across a wide range of everyday objects, and participants. The force strength estimates correlate with estimates produced by pressure-based devices, and can also determine the correct hand grip strength category with up to 86% accuracy. Our findings also suggest that users prefer our approach to existing solutions as HIPPO blends the estimation with everyday interactions. https://dl.acm.org/doi/10.1145/35703442023ZYZhigang Yin et al.Fitness Tracking & Physical Activity MonitoringBiosensors & Physiological MonitoringUbiComp
The CAT Effect: Exploring the Impact of Casual Affective Triggers on Online Surveys' Response RatesWe explore the impact of Casual Affective Triggers (CAT) on response rates of online surveys. As CAT, we refer to objects that can be included in survey participation invitations and trigger participants' affect. The hypothesis is that participants who receive CAT-enriched invitations are more likely to respond to a survey. We conducted a study where the control condition received invitations without affective triggers, and the experimental condition received CAT-enriched invitations. We differentiated the triggers within the experimental condition: one-third of the population received a personalized invitation, one-third received a picture of the surveyor's cat, and one-third received both. We followed up with a survey to validate our findings. Our results suggest that CATs have a positive impact on response rates. We did not find CATs to induce response bias.2022ICIrene-Angelica Chounta et al.University of Duisburg-EssenParticipatory DesignUser Research Methods (Interviews, Surveys, Observation)CHI
What Happens to All These Hackathon Projects? - Identifying Factors to Promote Hackathon Project ContinuationTime-based events, such as hackathons and codefests, have become a global phenomenon attracting thousands of participants to hundreds of events every year. While research on hackathons has grown considerably, there is still limited insight into what happens to hackathon projects after the event itself has ended. While case studies have provided rich descriptions of hackathons and their aftermath, we add to this literature a large-scale quantitative study of continuation across hackathons in a variety of domains. Our findings indicate that a considerable number of projects get continued after a hackathon has ended. Our results also suggest that technical preparation, number of technologies used in a project and winning a hackathon can contribute to short-term continuation while long-term continuation is predicated on skill diversity among team members, their technical capabilities in relationship to the technologies used in a project and their intention to expand the reach of a project. Moreover, we found intensive short-term activity to be associated with a lower likelihood of long-term project continuation.2020ANAlexander Nolte et al.Coordination and CollaborationCSCW
When to say “Enough is Enough!”: A Study on the Evolution of Collaboratively Created Process ModelsOrganizations conduct series of face-to-face meetings aiming to improve work practices. In these meetings, participants from different backgrounds collaboratively design artifacts, such as knowledge or process maps. Such meetings are orchestrated and carried out by facilitators and the success of the meetings almost solely depends on the experience of the facilitators. Previous research has mainly focused on approaches that support facilitators and participants in the upfront planning of such events. There is however, little guidance for facilitators and participants once a meeting has started. One critical aspect – among others – is that during a meeting, the facilitator and participants need to decide for how long the iterative process of discussion and design should continue. We argue that we can provide support for such decisions based on the evolution of artifacts collaboratively created during such meetings. This paper presents a multi-level, multi-method analysis of artifacts based on experts’ observations in combination with network analytics. We study the use of automated analytics to assess the evolution of collaboratively created artifacts and to indicate maturity and established consensus of the collaborative practice. We propose a computational approach to support facilitators and participants in deciding when to stop face-to-face meetings.2018ICIrene-Angelica Chounta et al.Meetings and Decision MakingCSCW