The growing use of AI in public administration improves efficiency, yet its use in discretionary decisions raises concerns about fairness and legitimacy. While prior research examined decision stakes and Human–AI decision-making configurations separately, their combined effect on citizens’ perceptions of fairness and adoption remains underexplored. We conducted a mixed-method Wizard-of-Oz study (n=43) using an Intelligent-Self-Service-Kiosk. Participants completed a low-stakes (ID-renewal) and a high-stakes (social-housing) task under one of three decision-making configurations: AI alone, AI with human-supervision, and human with AI advice or recommendation. Quantitative analysis found no significant effects, highlighting the limits of standard metrics. However, qualitative interviews revealed that citizens valued human involvement, requiring meaningful over symbolic oversight. They emphasized interactive dialogue before decisions to capture their circumstances and after, to facilitate appeals. We contribute evidence of tensions between citizens’ desire for efficiency and need for human-control and fairness. We provide guidance for designing citizen-centered AI systems that align with democratic values.

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Advances in emerging technologies, such as on-body mechanical actuators and electrical muscle stimulation, have allowed computers to take control over our bodies. This presents opportunities as well as challenges, raising fundamental questions about agency and the role of our bodies when interacting with technology. To advance this research field as a whole, we brought together expert perspectives in a week-long seminar to articulate the grand challenges that should be tackled when it comes to the design of computers’ control over our bodies. These grand challenges span technical, design, user, and ethical aspects. By articulating these grand challenges, we aim to begin initiating a research agenda that positions bodily control not only as a technical feature but as a central, experiential, and ethical concern for future human–computer interaction endeavors.

Automated vehicles (AVs) reached technological maturity and will soon arrive on streets as traffic participants.Human traffic participants such as drivers, pedestrians, or cyclists will be increasingly confronted with the presence of AVs within their environment, not necessarily knowing or understanding what to expect and how to interact with them.Although AVs are designed to act safely, effective interaction in mixed traffic scenarios will depend on successful communication, interaction, or even negotiation beyond static rules and regulations.Prosocial behavior, such as yielding one's right of way, will be needed to resolve unclear traffic situations or foster traffic flow.However, what are the characteristics of such prosocial behavior, and how to measure this not only for automated vehicles

Smart homes are evolving into complex ecosystems, but their inner workings often remain opaque to users, limiting their ability to troubleshoot and customise the technology. The distributed and hidden components make it challenging for users to understand how these systems work. To design interfaces that enable intuitive troubleshooting for non-experts, we first need a clear understanding of how they form mental models and instinctively diagnose issues. We conducted three iterative vignette studies with realistic smart home scenarios to explore how users perceive interconnectivity in smart home ecosystems and how system complexity impacts their troubleshooting approaches. We identified common smart home topologies envisioned by users and categorised their diagnostic strategies. Our findings show that while users view their smart homes as hierarchical, their mental models are often incomplete, and current interfaces favour functional models, hiding the connections in the system. We provide seven actionable takeaways for designing interfaces that improve user understanding and troubleshooting capabilities.

Current smart home technologies rely on touchscreens and voice assistants for interaction. These interfaces lack tactile engagement and fail to support users’ daily routines and preferences, leading to poor user experiences (UX). Designing tangible user interfaces (TUIs) that align with user preferences can improve the status quo. This paper explores the potential of TUIs using everyday objects for smart home control. Four prototypes — a vase, pillow, coaster, and flower — were evaluated for UX and metaphor alignment through a within-subjects study with 25 participants. Using meCUE questionnaires and semi-structured interviews, we examined how physical and contextual attributes influence UX. Our findings indicate that everyday objects are effective TUI and produce positive UX, provided careful consideration is given to their physical and contextual attributes. This research expands our understanding of TUIs’ role in bridging the digital-physical divide and offers practical guidelines for embedding intuitive smart home controls into everyday objects.

Smart home appliances are becoming more popular, yet their user interfaces (UI) often lack integration into living spaces and daily practices. To facilitate more natural interactions, reduce clutter and promote better integration in our living spaces, we propose embedding controls into everyday objects. This paper outlines our approach in three steps: identifying suitable household objects through ethnographic research, gathering interaction ideas via user gesture elicitation, and evaluating the intuitiveness of conceptual interfaces through a Wizard-of-Oz study. Our findings suggest that an object's primary function has less influence on its potential as a smart home controller. Instead, its location, physical characteristics, and intuitive affordances play a more significant role in shaping its potential. Designers should, therefore, focus on making these affordances easily discoverable by concurrently considering the object's physical properties, function, and interaction context.

Small-size autonomous vehicles have reached a level of technological maturity that enables their use as efficient means for goods delivery. Yet, current designs of both ground and aerial vehicles fail to address potential information needs of bystanders: What is this robot doing? Can it harm me? Does it need help? Through a series of six co-design workshops ( \(N = 22\) ), we iteratively explore two types of autonomous healthcare delivery vehicles, namely aerial and ground robots, with a focus on bystanders’ perspectives and interaction needs between bystanders and AVs. The resulting design propositions were then synthesized into functional scale-model prototypes of a healthcare delivery robot and drone. We validate our co-design findings by conducting two laboratory Wizard-of-Oz experiments ( \(N = 24\) ). Our results demonstrate how familiar colors and iconography support goal sharing and bystanders in recognizing the delivery vehicle’s purpose and intentions. Mapping interaction needs of bystanders, we find contextual effects on bystander attitudes and the effectiveness of communication modalities. This work contributes to the design of future, socially acceptable small-size delivery vehicles fit for human spaces.

In this paper, banking services, as the research object to explore the relationship among distributive fairness, procedural fairness, interactive fairness and informational fairness. The study found: informational fairness significant impact on the ...

HCI research has been instrumental in enabling self-directed health tracking. Despite a plethora of devices and data, however, users’ views of their own health are often fragmented. This is a problem for women’s health, where physical and mental observations and symptoms are strongly intertwined. An integrated view throughout different life stages could help to better understand these connections, facilitate symptom alleviation through life-style changes, and support timely diagnosis: currently, women’s health issues often go under-researched and under-diagnosed. To capture the needs and worries of self-directed tracking, interpreting and sharing women’s health data, we held workshops with 28 women. Drawing upon feminist methods, we conducted a Reflexive Thematic Analysis to identify six central themes that ground opportunities and challenges for life-long, self-directed tracking of intimate data. These themes inform the design of tools for data collection, analysis and sharing that empower women to better understand their bodies and demand adequate health services.

Gesture interactions have become ubiquitous, and with increasingly reliable sensing technology we can anticipate their use in everyday environments such as smart homes. Gestures must meet users’ needs and constraints in diverse scenarios to gain widespread acceptance. Although mid-air gestures have been proposed in various user contexts, it is still unclear to what extent users want to integrate them into different scenarios in their smart homes, along with the motivations driving this desire. Furthermore, it is uncertain whether users will remain consistent in their suggestions when transitioning to alternative scenarios within a smart home. This study contributes methodologically by adapting a bottom-up frame-based design process. We offer insights into preferred devices and commands in different smart home scenarios. Using our results, we can assist in designing gestures in the smart home that are consistent with individual needs across devices and scenarios, while maximizing the reuse and transferability of gestural knowledge.

The vision of a ‘metaverse’ may soon bring a ubiquitous(ly) Augmented Reality (UAR) delivering context-aware, geo-located, and continuous blends of real and virtual elements into reach. This paper draws on speculative design to explore, question, and problematize consequences of AR becoming pervasive. Elaborating on Desjardin et al.’s bespoke booklets, we co-speculate together with 12 globally dispersed participants. Each participant received a custom-made design workbook containing pictures of their immediate surroundings, which they elaborated on in situated brainstorming activities. We present an integration of their speculative ideas and lived experiences in 3 overarching themes from which 7 ‘dark’ scenarios caused by UAR were formed. The Scenarios are indicative of deceptive design patterns that can (and likely will be) devised to misuse UAR, and anti-patterns that could cause unintended consequences. These contributions enable the timely discussion of potential antidotes and to which extent they can mitigate imminent harms of UAR.

Automated vehicles (AVs) are expected to encounter various ambiguous space-sharing conflicts in urban traffic. Bottleneck scenarios, where one of the parts needs to resolve the conflict by yielding priority to the other, could be utilized as a representative ambiguous scenario to understand human behavior in experimental settings. We conducted a controlled field experiment with a Wizard of Oz automated car in a bottleneck scenario. 24 participants attended the study by driving their own cars. They made yielding, or priority-taking decisions based on implicit and explicit locomotion cues on AV realized with an external display. Results indicate that acceleration and deceleration cues affected participants’ driving choices and their perception regarding the social behavior of AV, which further serve as ecological validation of related simulation studies.

Mid-air gesture-based systems are becoming ubiquitous. Many mid-air gestures control different kinds of interactive devices, applications, and systems. They are, however, still targeted at specific devices in specific domains and are not necessarily consistent across domain boundaries. A comprehensive evaluation of the transferability of gesture vocabulary between domains is also lacking. Consequently, interaction designers cannot decide which gestures to use for which domain. In this systematic literature review, we contribute to the future research agenda in this area, based on an analysis of 172 papers. As part of our analysis, we clustered gestures according to the dimensions of an existing taxonomy to identify their common characteristics in different domains, and we investigated the extent to which existing mid-air gesture sets are consistent across different domains. We derived a consensus gesture set containing 22 gestures based on agreement rates calculation and considered their transferability across different domains.

As the world becomes more interconnected, physical separation between people increases. Existing collaborative Virtual Reality (VR) applications, designed to bridge this distance, are not yet sufficient in providing a sense of social connection comparable to face-to-face interactions. Possible reasons are the limited multimodality of VR systems and the lack of non-verbal cues in VR avatars. We systematically investigated how facial expressions influence Social Presence in two collaborative VR tasks. We explored four types of facial expressions: eyes and mouth movements, their combination, and no expressions, for two types of explanations: verbal and graphical. To examine how these expressions influence Social Presence, we conducted a controlled VR experiment (N = 48), in which participants had to explain a specific term to their counterpart. Our results demonstrate that eye and mouth movements positively influence Social Presence in VR. Particularly, combining verbal explanations and eye movements induces the highest feeling of co-presence.

Over the last decade, smart home technology (SHT) has become an integral part of modern households. As a result, smart home ecosystems blend with daily social life, appropriated and integrated into personalised domestic environments. The lived experience of inhabiting smart home ecosystems, however, is not yet understood, resulting in a mismatch between ecosystem design and inhabitants’ needs. Drawing on contextual inquiry methods, we conducted an explorative interview study (N=20) with SHT users in their homes. Our thematic analysis reveals how users shape their smart home ecosystems (SHEs), considering social relationships at home, perceived ownership of SHTs, and expected key benefits. Notably, our analysis shows that household members consciously choose ‘their’ level of SHT interconnectedness, reflecting social, spatial and functional affinities between systems. Following our findings, we formulate five implications for designing future SHTs. Our work contributes insights on the dynamics and appropriation of smart home ecosystems by their inhabitants.

Assessing visual aesthetics is important for organizing and retrieving photos. That is one reason why several works aim to automate such an assessment using deep neural networks. The underlying models, however, lack explainability. Due to the subjective nature of aesthetics, it is challenging to find objective ground truths and explanations for aesthetics based on them. Hence, such models are prone to socio-cultural biases that come with the data, which raises questions on a wide range of ethical and technical issues. This paper presents an explainable artificial intelligence framework that adapts and combines three types of explanations for the concept of aesthetic assessment: 1) model constraints for built-in interpretability, 2) analysis of perturbation impacts on decisions, and 3) generation of artificial images that represent maxima or minima of values in the latent feature space. The objective is to improve human understanding through the explanations by creating an intuition for the model’s decision making. We identify issues that arise when humans interact with the explanations and derive requirements from human feedback to address the needs of different user groups. We evaluate our novel interactive explainable artificial intelligence technology in a study with end users (N=20). Our participants have different levels of experience in deep learning, allowing us to include experts, intermediate users, and laypersons. Our results show the benefits of the interactivity of our approach. All users found our system helpful in understanding how the aesthetic assessment was executed, reporting varying needs for explanatory details.

While the neck-worn garments are an integral part of fashion around the world, few interactive systems utilize them as form factors. As neck is located beyond the natural field of view, it offers wide opportunities for subtle haptic interaction. While tactile acuity of the neck is well studied in clinical research, these results are difficult to apply for interactive systems. In this paper, we present HaptiCollar - a research prototype for studying tactile acuity of the neck. We conducted two experimental studies comparing different numbers of actuators on the neck, in two contextual scenarios simulating stationary and mobile use. We found that pattern actuations are recognised more effectively than single-point vibrations, independently of use scenario. Our analysis shows that introducing a primary cognitive task and motion does not impair recognition accuracy, while highly increasing the cognitive load. Our work contributes empirical insights for designing haptic interaction for future neck-worn interfaces.

Conducting gesture elicitation studies (GES) in personal spaces such as smart homes is crucial to achieving high ecological validity of elicited gestures. However, supervising such studies is considered intrusive and negatively affects the results' quality. The alternative is to conduct unsupervised GES under similar conditions, but more side-by-side comparisons documenting the similarities and differences between both approaches are necessary. Consequently, we need more data describing the preferred approach and whether the differences or similarities in the results are so significant to cause concern. This research distributed a DIY observation kit, which 30 participants assembled and used to propose gestures for controlling elements in a smart living room using a pillow's surface, with and without supervision. Our results show that gestures from supervised and unsupervised studies differ in quantity and max-consensus but not in gesture Agreement Scores. Our results also show that participants preferred conducting unsupervised studies but proposed fewer gesture sets in this condition.

Road traffic is strongly regulated, however informal communication is essential whenever formal rules are flexibly treated. Consequently, conflict-avoidant automated vehicles (AVs) can be disadvantaged when humans do not behave prosocially towards them. This can lead to disruptions of mixed traffic, where human and automated driving co-exists. Equipping AVs with sympathy-eliciting external Human-Machine Interfaces (eHMI) mimicking informal communication cues could mitigate this challenge by fostering the prosocial behavior of drivers. This work contributes video vignettes that are experimentally validated in an online survey (N=90). While we found participants to not behave differently towards human-controlled and baseline automated vehicles, eHMIs were potent in eliciting sympathy and encouraged yielding behavior. This effect was more pronounced when the interface signaled an urgent situation or indicated prolonged waiting times. Non-yielding behavior was rationalized based on priority rules. These results emphasize how fostering prosocial behavior in traffic can be achieved via sympathy-eliciting external displays.

For an improved user experience in smart homes, there is a need to enhance the current interaction methods by embedding control interfaces in everyday household objects. Embedded interfaces will allow smart home inhabitants to control their surroundings using more familiar interaction concepts and techniques than those imposed by appliance manufacturers and vendors. However, to achieve this state, technology designers need to understand the behaviours and attitudes of end users when they interact with different elements of a smart home using everyday objects as control media. We present a set of exploratory investigations focused on understanding the behaviours and attitudes of end-users as they control elements of a fictional smart home. Accordingly, we investigate how two highly different locations and form factors -- a table surface and a couch pillow -- impact user expectations about gestures used to control various smart home features. To this end, we conducted explorative elicitation with 14 participants. Our results highlight that an object's physicality significantly impacts the types of gestures users perceive as intuitive and that deforming an interface has the potential to bring playfulness to interaction. Following our observations, we formulated four design implications for conceiving interaction modalities with deformable interfaces for domestic environments.

Personal photo collections today usually include a huge number of convenience images (i.e. images with a practical character, such as handwritten notes, flipchart drawings, WI-FI logins or car parking positions). This paper proposes an iterative approach for the automatic recognition of convenience photos combining the methods from user-centered design and deep learning. In the first stage, we conducted a study to specify the categories of photos typically perceived by users as convenience photos. We then employed the specified categories to generate semi-automatically a dataset for training and testing a convolutional neural network model. After an evaluation of this model using from owners self-rated personal photo collections, we were able to improve both the quality of the dataset and our model. This paper therefore demonstrates the importance of integrating users at different stages of the development of deep learning solutions.

Reading is a key skill in learning, working and participating in society on all levels. However, in 2018, 20% of German school students possessed only insufficient levels of reading proficiency. Frustration associated with these difficulties results in avoidance of reading, such that struggling readers will often not overcome them on their own. We present a first approach towards an assistance system that recognizes reading difficulties by analyzing the user's gaze behavior and offers dynamic adaptation of the text presentation. In a formative study, including 34 fifth-grade students, letter- and syllabication-based assistance significantly and substantially increased children's motivation to read. Based on these findings, gaze-contingent assistance presents a promising approach in improving struggling readers’ reading experience and motivation to read.

With the increasing ubiquity of personal devices, social acceptability of human-machine interactions has gained relevance and growing interest from the HCI community. Yet, there are no best practices or established methods for evaluating social acceptability. Design strategies for increasing social acceptability have been described and employed, but so far not been holistically appraised and evaluated. We offer a systematic literature analysis (N=69) of social acceptability in HCI and contribute a better understanding of current research practices, namely, methods employed, measures and design strategies. Our review identified an unbalanced distribution of study approaches, shortcomings in employed measures, and a lack of interweaving between empirical and artifact-creating approaches. The latter causes a discrepancy between design recommendations based on user research, and design strategies employed in artifact creation. Our survey lays the groundwork for a more nuanced evaluation of social acceptability, the development of best practices, and a future research agenda.

Recent advances in Virtual Reality (VR) technology, such as larger fields of view, have made VR increasingly immersive. However, a larger field of view often results in a user focusing on certain directions and missing relevant content presented elsewhere on the screen. With HiveFive, we propose a technique that uses swarm motion to guide user attention in VR. The goal is to seamlessly integrate directional cues into the scene without losing immersiveness. We evaluate HiveFive in two studies. First, we compare biological motion (from a prerecorded swarm) with non-biological motion (from an algorithm), finding further evidence that humans can distinguish between these motion types and that, contrary to our hypothesis, non-biological swarm motion results in significantly faster response times. Second, we compare HiveFive to four other techniques and show that it not only results in fast response times but also has the smallest negative effect on immersion.

Not only the current coronavirus is holding the world in breath. Beyond this current health crisis the world is facing several global challenges from climate change and environmental damage, access to clean water and food, socio-economic inequalities to name a few. The United have very well framed these global challenges in their 17 Sustainability Goals for a future in prosperity and equal opportunities for all, to be achieved by 2030. There is no one simple solution, no one easy cure in sight to address these pressing challenges of our days. Rather a collective approach of all of us is needed which in sum will be contributing to these. Obviously, the field of multimedia has contributed to many tools and applications that are so much in demand these days to stay connected while keeping the distance. But there is much more we can offer to our common digital future. Our future health system, global access to education, decent work, and reducing inequalities are just some of these goals where we our field can contribute. In this panel we will discuss which path we could follow.

Locating objects in the environment can be a difficult task, especially when the objects are occluded. With Augmented Reality, we can alternate our perceived reality by augmenting it with visual cues or removing visual elements of reality, helping users to locate occluded objects. However, to our knowledge, it has not yet been evaluated which visualization technique works best for estimating the distance and size of occluded objects in optical see-through head-mounted Augmented Reality. To address this, we compare four different visualization techniques derived from previous work in a laboratory user study. Our results show that techniques utilizing additional aid (textual or with a grid) help users to estimate the distance to occluded objects more accurately. In contrast, a realistic rendering of the scene, such as a cutout in the wall, resulted in higher distance estimation errors.

The papers in this special section is to broadly engage the machine learning and multimedia communities on the emerging yet challenging interpretable machine learning. Multimedia is increasingly becoming the “biggest big data,” among the most important and valuable source for insight and information. Many powerful machine learning algorithms, especially deep learning models such as convolutional neural networks (CNNs), have recently achieved outstanding predictive performance in a wide range of multimedia applications, including visual object classification, scene understanding, speech recognition, and activity prediction. Nevertheless, most deep learning algorithms are generally conceived as blackbox methods, and it is difficult to intuitively and quantitatively understand the results of their prediction and inference. Since this lack of interpretability is a major bottleneck in designing more successful predictive models and exploring wider-range useful applications, there has been an explosion of interest in interpreting the representations learned by these models, with profound implications for research into interpretable machine learning in the multimedia community.

Navigation systems for cyclists are commonly screen-based devices mounted on the handlebar which show map information. Typically, adult cyclists have to explicitly look down for directions. This can be distracting and challenging for children, given their developmental differences in motor and perceptual-motor abilities compared with adults. To address this issue, we designed different unimodal cues and explored their suitability for child cyclists through two experiments. In the first experiment, we developed an indoor bicycle simulator and compared auditory, light, and vibrotactile navigation cues. In the second experiment, we investigated these navigation cues in-situ in an outdoor practice test track using a mid-size tricycle. To simulate road distractions, children were given an additional auditory task in both experiments. We found that auditory navigational cues were the most understandable and the least prone to navigation errors. However, light and vibrotactile cues might be useful for educating younger child cyclists.

Eyewear devices, such as augmented reality displays, increasingly integrate eye tracking, but the first-person camera required to map a user's gaze to the visual scene can pose a significant threat to user and bystander privacy. We present PrivacEye, a method to detect privacy-sensitive everyday situations and automatically enable and disable the eye tracker's first-person camera using a mechanical shutter. To close the shutter in privacy-sensitive situations, the method uses a deep representation of the first-person video combined with rich features that encode users' eye movements. To open the shutter without visual input, PrivacEye detects changes in users' eye movements alone to gauge changes in the "privacy level" of the current situation. We evaluate our method on a first-person video dataset recorded in daily life situations of 17 participants, annotated by themselves for privacy sensitivity, and show that our method is effective in preserving privacy in this challenging setting.

Managing one's health is among the most personal and most important challenges. HealthMedia can be viewed as one response from the multimedia community to rise to this challenge. There is an increasing number of research work that shows how core multimedia research is becoming an important enabler for solutions with applications and relevance for the societal questions of health. Within this workshop, we continue to explore the relevance, contribution and future directions of multimedia to health care and personal health. This workshop brings together researchers from diverse topics such as multimedia, tracking, lifelogging, accessibility, HCI, but also health, medicine, and psychology to address challenges and opportunities of multimedia in and for health.

Multimedia research has now moved beyond laboratory experiments and is rapidly being deployed in real-life applications including advertisements, social interaction, search, security, automated driving, and healthcare. Hence, the developed algorithms now have a direct impact on the individuals using the abovementioned services and the society as a whole. While there is a huge potential to benefit the society using such technologies, there is also an urgent need to identify the checks and balances to ensure that the impact of such technologies is ethical and positive. This panel will bring together an array of experts who have experience collecting large-scale datasets, building multimedia algorithms, and deploying them in practical applications, as well as, a lawyer whose eyes have been on the fundamental rights at stake. They will lead a discussion on the ethics and lawfulness of dataset creation, licensing, privacy of individuals represented in the datasets, algorithmic transparency, algorithmic bias, explainability, and the implications of application deployment. Through an interactive process engaging the audience, the panel hopes to: increase the awareness of such concepts in the multimedia research community; initiate a discussion on community guidelines all for setting the future direction of conducting multimedia research in a lawful and ethical manner.

Child cyclists are at greater risk for car-to-cyclist accidents than adults. This is in part due to developmental differences in the motor and perceptual-motor abilities of children and adults, and missing cycling infrastructure. To address these issues, we examine unimodal and projection-based techniques to support children in maintaining a good lane position in the absence of bicycle lanes. We present safety-relevant information using unimodal cues: vibration on the handlebar, ambient light in a cycle helmet, projected heads-up display indicators, and on-road laser projection. As a first step, we interviewed twelve children about their cycling issues. We then conducted a lab experiment (N=25) in a bicycle simulator using the unimodal cues in the presence of a visual search task, followed by a controlled test-track experiment (N=15). We found that cycling performance with lane keeping cues was comparable to situations without them, however children found them helpful and expressed subjective preferences for the LED helmet and vibration on the handlebar.

Knowing the locations of spatially distributed objects is important in many different scenarios (e.g., driving a car and being aware of other road users). In particular, it is critical for preventing accidents with objects that come too close (e.g., cyclists or pedestrians). In this paper, we explore how peripheral cues can shift a user's attention towards spatially distributed out-of-view objects. We identify a suitable technique for visualization of these out-of-view objects and explore different cue designs to advance this technique to shift the user's attention. In a controlled lab study, we investigate non-animated peripheral cues with audio stimuli and animated peripheral cues without audio stimuli. Further, we looked into how user's identify out-of-view objects. Our results show that shifting the user's attention only takes about 0.86 seconds on average when animated stimuli are used, while shifting the attention with non-animated stimuli takes an average of 1.10 seconds.

The following topics are dealt with: feature extraction; learning (artificial intelligence); image representation; video signal processing; convolution; image classification; image retrieval; feedforward neural nets; image colour analysis; image segmentation.

This paper investigates bias in coverage between Western and Arab media on Twitter after the November 2015 Beirut and Paris terror attacks. Using two Twitter datasets covering each attack, we investigate how Western and Arab media differed in coverage bias, sympathy bias, and resulting information propagation. We crowdsourced sympathy and sentiment labels for 2,390 tweets across four languages (English, Arabic, French, German), built a regression model to characterize sympathy, and thereafter trained a deep convolutional neural network to predict sympathy. Key findings show: (a) both events were disproportionately covered (b) Western media exhibited less sympathy, where each media coverage was more sympathetic towards the country affected in their respective region (c) Sympathy predictions supported ground truth analysis that Western media was less sympathetic than Arab media (d) Sympathetic tweets do not spread any further. We discuss our results in light of global news flow, Twitter affordances, and public perception impact.

Take-over requests (TORs) in highly automated vehicles are cues that prompt users to resume control. TORs however, are often evaluated in non-moving driving simulators. This ignores the role of motion, an important source of information for users who have their eyes off the road while engaged in non-driving related tasks. We ran a user study in a moving-base driving simulator to investigate the effect of motion on TOR responses. We found that with motion, user responses to TORs vary depending on the road context where TORs are issued. While previous work showed that participants are fast to respond to urgent cues, we show that this is true only when TORs are presented on straight roads. Urgent cues issued on curved roads elicit slower responses than non-urgent cues on curved roads. Our findings indicate that TORs should be designed to be aware of road context to accommodate natural user responses.

Grandparents and grandchildren that live apart often rely on communication technologies, such as messengers, video conferencing, and phone calls for maintaining relationships. While some of these systems are challenging for grandparents, others are less engaging for children. To facilitate communication, we developed StoryBox, a tangible device that allows sharing photos, tangible artifacts, and audio recordings of everyday life. We conducted a preliminary study with two families to identify design issues, and further refine the prototype. Subsequently, we conducted a field study with four families for up to four weeks to better understand real-world use and examine inter-generational connectedness. We found that StoryBox was accessible, simple, and helped bridge the technological gap between grandparents and grandchildren. Children communicated asynchronously in a playful and idiosyncratic manner, and grandparents shared past family memories. We provide insights on how to ease communication between different generations, engage them in sharing activities, and strengthen family relationships.

Mixed Reality devices can either augment reality (AR) or create completely virtual realities (VR). Combined with head-mounted devices and eye-tracking, they enable users to interact with these systems in novel ways. However, current eye-tracking systems are expensive and limited in the interaction with virtual content. In this paper, we present EyeMR, a low-cost system (below 100$) that enables researchers to rapidly prototype new techniques for eye and gaze interactions. Our system supports mono- and binocular tracking (using Pupil Capture) and includes a Unity framework to support the fast development of new interaction techniques. We argue for the usefulness of EyeMR based on results of a user evaluation with HCI experts.

Highly automated vehicles, occasionally require users to resume vehicle control from non-driving related tasks by issuing cues called take-over request (TOR). Due to being engaged in non-driving related tasks (NDRT), users have a decreased level of situational awareness of the driving context. Therefore, user interface designs for TORs should ensure smooth transitions from the NDRTs to vehicle control. In this paper, we investigated the role of decision priming cues as TORs across different levels of NDRT engagement. In a driving simulator, users performed a reading span task while driving in automated mode. They received audio-visual TORs which primed them with an appropriate maneuver (steering vs. braking), depending on the traffic situation. Our results showed that priming users with upcoming maneuvers results in faster responses and longer time to collision to obstacles. However, the level of engagement in NDRT does not affect user responses to TORs.

Head-mounted devices (HMDs) for Virtual and Augmented Reality (VR/AR) enable us to alter our visual perception of the world. However, current devices suffer from a limited field of view (FOV), which becomes problematic when users need to locate out of view objects (e.g., locating points-of-interest during sightseeing). To address this, we developed and evaluated in two studies HaloVR, WedgeVR, HaloAR and WedgeAR, which are inspired by usable 2D off-screen object visualization techniques (Halo, Wedge). While our techniques resulted in overall high usability, we found the choice of AR or VR impacts mean search time (VR: 2.25s, AR: 3.92s) and mean direction estimation error (VR: 21.85°, AR: 32.91°). Moreover, while adding more out-of-view objects significantly affects search time across VR and AR, direction estimation performance remains unaffected. We provide implications and discuss the challenges of designing for VR and AR HMDs.

Current head-mounted displays (HMDs) for Virtual Reality (VR) and Augmented Reality (AR) have a limited field-of-view (FOV). This limited FOV further decreases the already restricted human visual range and amplifies the problem of objects going out of view. Therefore, we explore the utility of augmenting HMDs with RadialLight, a peripheral light display implemented as 18 radially positioned LEDs around each eye to cue direction towards out-of-view objects. We first investigated direction estimation accuracy of multi-colored cues presented on one versus two eyes. We then evaluated direction estimation accuracy and search time performance for locating out-of-view objects in two representative 360° video VR scenarios. Key findings show that participants could not distinguish between LED cues presented to one or both eyes simultaneously, participants estimated LED cue direction within a maximum 11.8° average deviation, and out-of-view objects in less distracting scenarios were selected faster. Furthermore, we provide implications for building peripheral HMDs.

Child cyclists are often at greater risk for traffic accidents. This is in part due to the development of children's motor and perceptual-motor abilities. To facilitate road safety for children, we explore the use of multimodal warning signals to increase their awareness and prime action in critical situations. We developed a bicycle simulator instrumented with these signals and conducted two controlled experiments. We found that participants spent significantly more time perceiving visual than auditory or vibrotactile cues. Unimodal signals were the easiest to recognize and suitable for encoding directional cues. However, when priming stop actions, reaction time was shorter when all three modalities were used simultaneously. We discuss the implications of these outcomes with regard to design of safety systems for children and their perceptual-motor learning.

Research in multimedia and health is driven by the current technological advancements in sensors and personalized healthcare. There is an increasing amount of work that shows how core multimedia research is becoming an important enabler for solutions with applications and relevance for the societal questions of health. This workshop brings together researchers from diverse topics such as multimedia, pervasive health, lifelogging, accessibility, HCI, but also health, medicine, and psychology to address challenges and opportunities of multimedia in and for health.

Privacy notices aim to make users aware of personal data gathered and processed by a system. Body-worn cameras currently lack suitable design strategies for privacy notices that announce themselves and their actions tosecondary andincidental users, such as bystanders, when they are being used in public. Hypothesizing that the commonly used status LED is not optimal for this use case, due to being not sufficiently understandable, noticeable, secure and trustworthy, we explore design requirements of privacy notices for body-worn cameras. Following a two-step approach, we contribute incentives for design alternatives to status LEDs: Starting from 8 design sessions with experts, we discuss 8 physical design artifacts, as well as design strategies and key motives. Finally, we derive design recommendations of the proposed solutions, which we back based on an evaluation with 12 UX & HCI experts.

While performing multiple competing tasks at the same time, e.g., when driving, assistant systems can be used to create cues to direct attention towards required information. However, poorly designed cues will interrupt or annoy users and affect their performance. Therefore, we aim to identify cues that are not missed and trigger a quick reaction without changing the primary task performance. We conducted a dual-task experiment in an anechoic chamber with LED-based stimuli that faded in or turned on abruptly and were placed in the periphery or front of a subject. Additionally, a white noise sound was triggered in a third of the trials. The primary task was to react to visual stimuli placed on a screen in front. We observed significant effects on the response times in the screen task when adding sound. Further, participants responded faster to LED stimuli when they faded in.

Automation shortcomings in highly automated driving (level 3) might require the driver to take over vehicle control. When the vehicle issues a take-over request (TOR), the driver has to immediately comprehend the situation, which highly demands visual attention. Therefore, haptic channel has the potential to be used for conveying information about driving context at take-over to assist decision making. In this work, we introduce the concept and prototype design of a shape-changing steering wheel which conveys contextual information at take-over. We evaluated this concept in comparison with an identical wheel with vibration cues. Results showed that haptic cues on steering wheel at TOR reassure drivers of their decisions rather than assisting them in decision making, and overall workload ratings are decreased using vibration cues. To assist decision making, contextual haptic cues in level 3 should be located on-body or on drivers' seat.

Innovations often trigger objections before becoming widely accepted. This paper assesses whether a familiarisation over time can be expected for data glasses, too. While user attitudes towards those devices have been reported to be prevalently negative [14], it is still unclear, to what extent this initial, negative user attitude might impede adoption. However, indepth understanding is crucial for reducing barriers early in order to gain access to potential benefits from the technology. With this paper we contribute to a better understanding of factors affecting data glasses adoption, as well as current trends and opinions. Our multiple-year case study (N=118) shows, against expectations, no significant change towards a more positive attitude between 2014 and 2016. We complement these findings with an expert survey (N=51) investigating prognoses, challenges and discussing the relevance of social acceptability. We elicit and contrast a controversial spectrum of expert opinions, and assess whether initial objections can be overwritten. Our analysis shows that while social acceptability is considered relevant for the time being, utility and usability are more valued for long-term adoption.

Activity trackers are frequently used in health and well-being, but their application in effective interventions is challenging. While research for reasons of use and non-use is ongoing, little is known about the way activity trackers are used in everyday life and over longer periods. We analyzed data of 104 individuals over 14,413 use days, and in total over 2.5 years. We describe general tracker use, periodic changes and overall changes over time, and identify characteristic patterns. While the use of trackers shows large individual heterogeneity, from our findings we could identify and classify general patterns for activity tracker use such as try-and-drop, slow-starter, experimenter, hop-on hop-off, intermittent and power user. Our findings contribute to the body of knowledge towards the successful design of effective health technologies, health interventions, and long-term health applications.

Various off-screen visualization techniques that point to off-screen objects have been developed for small screen devices. A similar problem arises with head-mounted Augmented Reality (AR) with respect to the human field-of-view, where objects may be out of view. Being able to detect so-called out-of-view objects is useful for certain scenarios (e.g., situation monitoring during ship docking). To augment existing AR with this capability, we adapted and tested well-known 2D off-screen object visualization techniques (Arrow, Halo, Wedge) for head-mounted AR. We found that Halo resulted in the lowest error for direction estimation while Wedge was subjectively perceived as best. We discuss future directions of how to best visualize out-of-view objects in head-mounted AR.

Nowadays, Mixed and Virtual Reality devices suffer from a field of view that is too small compared to human visual perception. Although a larger field of view is useful (e.g., conveying peripheral information or improving situation awareness), technical limitations prevent the extension of the field-of-view. A way to overcome these limitations is to extend the field-of-view with peripheral light displays. However, there are no tools to support the design of peripheral light displays for Mixed or Virtual Reality devices. Therefore, we present our prototyping tool PeriMR that allows researchers to develop new peripheral head-mounted light displays for Mixed and Virtual Reality.

Though still a rare sight, body-worn lifelogging cameras such as Mofily's YoCam or the Narrative Clip have become increasingly popular amongst tech-savvy audiences. In this paper, we investigate whether users of those devices prefer to wear them openly or in a concealed, less obtrusive manner. We discuss the camouflage of lifelogging cameras based on results from an online study (N=117), including the why (not) and how as well as qualitative insights on how social contexts influence usage habits. The results of our study provide empirical evidence that deliberate concealment can be perceived unethical, and that moderate noticeability is favoured. We furthermore found contrary effects of lifelogging cameras in interpersonal relationships, including self-censorship by the user, avoidance behaviour by her/his peers and conversation starting character of the device itself. We conclude by highlighting design challenges concerning ubiquitous, body-worn cameras.

Ever since the emergence of digitization, we've used the term multimedia to represent a combination of different kinds of media types, such as images, audio, and videos. As new sensing technologies emerge and are now becoming omnipresent in daily lives, the definition, role and significance of multimedia is changing. Multimedia now represents the means for communicating, cooperating, and also for monitoring numerous aspects of daily life, at various levels of granularity and application, ranging from personal to societal. With this shift, we have since moved from comprehending single media and its state toward comprehending media in terms of its use context.

Most of today's wearable devices mainly focus on functionality and show large deficits in aesthetics and comfort. However, researchers and market analysts emphasise the importance of aesthetics for wearable technology to be successful. Smart Digital Jewellery has been proposed as an approach to seamlessly integrate technology into appealing, body-worn objects. In this work, we investigated how a smart digital multi-purpose bracelet should be designed in order to be attractive, functional, easily comprehensible, and easy to manage. We built the Tangible Apps Bracelet and evaluated it in a lab study. The Tangible Apps Bracelet integrates multiple applications in form of single elements that are threaded on a string. Participants experienced it very positively, easy to interact with, and rated its usability and user experience as very good. They particularly appreciated its simple interaction and display concept and the seamless integration of applications and digital components into an aesthetic piece of jewellery.

Time is a complex concept that takes children years to learn. Yet, many of their activities are bounded by time constraints. We aim to support children in learning time with intuitive interaction with a prototype presenting time periods unobtrusively. We present Timelight, an ambient light display designed to help children better understand the duration of time periods. We derive requirements from interviews and a focus groups with teachers, parents and HCI experts. We establish an interaction design and develop a prototype for a field exploration study. We explore the functionality of and interaction with Timelight in families, kindergarten groups and school classes in a two-week field study. Our results show that ambient light is well suited to keep children updated on the duration of time in various contexts of their daily life. Our participants use Timelight on a vast range of occasions and identify additional roles for the display.

Take-over situations in highly automated driving occur when drivers have to take over vehicle control due to automation shortcomings. Due to high visual processing demand of the driving task and time limitation of a take-over maneuver, appropriate user interface designs for take-over requests (TOR) are needed. In this paper, we propose applying ambient TORs, which address the peripheral vision of a driver. Conducting an experiment in a driving simulator, we tested a) ambient displays as TORs, b) whether contextual information could be conveyed through ambient TORs, and c) if the presentation pattern (static, moving) of the contextual TORs has an effect on take-over behavior. Results showed that conveying contextual information through ambient displays led to shorter reaction times and longer times to collision without increasing the workload. The presentation pattern however, did not have an effect on take-over performance.

Truck platooning has advantages for fuel consumption, road safety, and use of the existing road infrastructure. However, it does not simplify the job of truck drivers who reportedly fear driving in close distance and mistrust the automation. Prior work indicates that a platooning assistant system can help overcoming these issues. However, there are no practical experiences with on-the-road platooning that shed light on how drivers perceive and evaluate such a system. In this work, we close this gap and present PlatoonPal, a platooning assistance system which we rigorously developed in a user centered way. We further present the results of a field test with three platooning trucks where drivers used PlatoonPal under real conditions. The results show that drivers are positive using the system and preferred information related closely to the current situation. We conclude the paper with guidelines for the future development of assistance systems for platooning.

In the last decade, several in-vehicle light displays have been proposed. These displays inform drivers via light patterns that go beyond simple status indicators. In this literature survey, we present 21 works with their light displays and patterns. In addition, we summarize the common methods and results of these works. This work will help researchers and designers find a good starting point for looking into in-vehicle light displays. It may further foster discussions about best practices in the community.

While HCI for development (HCI4D) research has typically focused on technological practices of poor and low-literate communities, little research has addressed how technology literate individuals living in a poor infrastructure environment use technology. Our work fills this gap by focusing on Lebanon, a country with longstanding political instability, and the wayfinding issues there stemming from missing street signs and names, a poor road infrastructure, and a non-standardized addressing system. We examine the relationship between technology literate individuals' navigation and direction giving strategies and their usage of current digital navigation aids. Drawing on an interview study (N=12) and a web survey (N=85), our findings show that while these individuals rely on mapping services and WhatsApp's share location feature to aid wayfinding, many technical and cultural problems persist that are currently resolved through social querying. We discuss our results in light of problems that any map user encounters in poor infrastructure environments.

Car navigation systems typically combine multiple output modalities; for example, GPS-based navigation aids show a real-time map, or feature spoken prompts indicating upcoming maneuvers. However, the drawback of graphical navigation displays is that drivers have to explicitly glance at them, which can distract from a situation on the road. To decrease driver distraction while driving with a navigation system, we explore the use of ambient light as a navigation aid in the car, in order to shift navigation aids to the periphery of human attention. We investigated this by conducting studies in a driving simulator, where we found that drivers spent significantly less time glancing at the ambient light navigation aid than on a GUI navigation display. Moreover, ambient light-based navigation was perceived to be easy to use and understand, and preferred over traditional GUI navigation displays. We discuss the implications of these outcomes on automotive personal navigation devices.

Ever since the emergence of digitization, the term multimedia has been used to represent a combination of different kinds of media types, such images, audio, and videos. As new sensing technologies emerge and are now becoming omnipresent in daily lives, the definition, role and significance of multimedia is changing. Multimedia now represents the means for communicating, cooperating, and also for monitoring numerous aspects of daily life, at various levels of granularity and application, ranging from personal to societal. With this shift, we have since moved from comprehending single media and its state toward comprehending media in terms of its use context. Multimedia is thus no longer confined to documentation and preservation, entertainment or personal media collections; rather, it has become an integral part of the tools and systems that are providing solutions to today's societal challenges-including challenges related to health care and personal health , aging, education, societal participation, sustainable energy, and intelligent transportation. Multimedia has thus evolved into a core enabler for future interactive and cooperative applications at the heart of society. In this workshop we explore the relevance and contribution of multimedia to health care and personal media.

We present the concept of an interactive image segmentation method, which allows a fast and precise extraction of foreground objects from natural images. The method is especially suited for mobile, touch-based devices. The approach combines automatic image segmentation with interactive refinement. In a first step, the user extracts an object using the first stage of the GrabCut algorithm. Any errors in the resulting segmentation can then be corrected via a novel correction step in which the underlying image is over-segmented into superpixels using the SLIC algorithm. The user can select individual superpixels in order to adjust the image segmentation. This image segmentation method is implemented as a full working demo on a Microsoft Surface Pro 3.

The exchange of daily moods is an important part of interpersonal communication over a distance. Mobile devices offer a platform for sharing on the go, and keeping in touch regularly. However, it is still a challenge to design an input for mood, such that the sharing easily integrates into the daily life and is engaging for a longer time. To design an input, which overcomes these challenges, we explore the use of four different methods for expressing mood on mobile devices, drawn from previous work in psychology. We aim to verify the usefulness of these methods and want to investigate this by conducting a comparative study of these four input methods, regarding the following factors: intuitiveness, inconvenience, speed of input, everyday use, expressiveness and overall suitability. Results show that use of photographs and emotion terms are suitable to describe the many facets of moods for most participants. Most of the participants prefer personalized input methods as well as combined methods. We discuss the outcomes with regard to the implications on future designs of messenger applications.

The number of assistance systems in cars has been increasing in recent years. While these systems are targeted at supporting the individual driver and his or her safety, they may though compete for the driver's attention, and may demand too much of the driver's cognitive resources. Based on the established multiple resource theory in recent years, the use of different multimodal displays has been investigated that give the driver attention while not overloading sensory channels. In our work, we are looking into peripheral light displays in means to present safety relevant information. In this paper, we present the results of an experiment in which a peripheral light display was used to show the distance to a closing vehicle. The display is an LED stripe, seamlessly integrated into the side door and the dashboard of the car. Two different light patterns were tested in an overtaking scenario in a driving simulator. One pattern encodes the expected time to collision to the left rear car by moving a light source towards the front left corner. The other pattern additionally adapts its brightness to a simplified model of the driver's certainty to get his or her attention in uncertain situations. In contrast to previous works, we did not focus on a warning system but on a decision aid system. We found that using the adaptive pattern led to faster decisions and therefore to a smaller probability of violating safety distances. We believe that this pattern is a good basis for patterns which are fine-tuned to individual drivers as well as better driver models.

In the recent years, several automotive manufacturers started to integrate ambient light displays into cars to increase drivers' comfort. Expanding their possible application areas, we propose a display that continuously informs the driver of the vehicle's as well as the environment's state. We studied this display in a lane change maneuver, in which a driver has to decide if he or she can change lane in front of a faster closing car or brake to keep a safe distance to a slower car in front. We present results of an experiment for light patterns that are based on results of a design workshop and definitions for lane change decision aid systems (LCDAS) of ISO 17387. Though we used ISO's definitions for the timings, our participants felt that status updates on the display came too late. In addition, the abrupt warnings, implemented in one of the tested patterns, led to worse performance of the participants. On the other hand, we observed that participants liked a continuous encoding of the time-to-collision (TTC) and observed a decrease in missed opportunities to overtake. Therefore, we argue that the defined limits for the warning levels are not well suited to support drivers during decision making in our scenario. Our contribution lies in a novel way of supporting drivers during lane change using an ambient in-vehicle light display. We showed that a continuous light pattern might help drivers in decision making, while more research has to be done to validate this.

Photo taking is more and more moving to mobile devices. With this transition, we observe that consumers are also directly editing and sharing photos. Editing of the whole image became very popular, for example with the filters Instagram offers. Some effects, however, require to edit a specific object of an image and for this an interactive segmentation is needed. This process is still tedious, as existing segmentation approaches focus on the algorithms rather than on the input methods. This paper explores different interaction techniques for image segmentation on mobile devices. We conducted two studies. The first to identify intuitive input methods and the second to evaluate the findings of the first study. As a result, we identified preferred gestures for the initial step to select a foreground object in an interactive image segmentation process. The results give first insights which input methods users intuitively use, how the users behave and what are the problems of the methods. This insights should be taken in consideration by the development of new interactive segmentation algorithms for mobile touch-based devices.

Recent interest in the development of ambient light systems has initialized a new research area, where the number of ambient light systems is expected to increase in the next years. To support the development of future ambient light systems, we need clear, explicit, and structured design guidelines. In this paper we present an evaluation of light patterns in a controlled laboratory study with two complementary parts. In the first part, our aim was to reveal and analyze light patterns that encode different types of everyday information. In the second part, we verified the results from the first part by asking another group of participants about their understanding of information encoded with light. Together, our results allowed us to establish light patterns and guidelines for building new ambient light systems and applications in the future.

Digital games are increasingly profiting from sensing technologies. However, their focus is mostly on sensing limb movements. We propose that sensing capabilities could also be used to engage players with proxemics: the interpersonal distance between players. We further add that wireless networks offer complementary distance zones for designers, offering novel design resources for digital play. We use our own as well as other games to articulate a set of strategies on how designers can utilize both proxemics and the new wireless proxemics to facilitate novel play experiences. Ultimately, with our work, we aim to expand the range of digital play.

Smart health systems such as networked activity trackers, scales, or sports watches allow monitoring many aspects of a healthy lifestyle. Nevertheless there is a semantic gap between these systems' measurements and the users' personal health action plan that is not bridged by existing health data aggregators. We describe representative types of health data as measured today and suggest a simple classification of data based on temporality of the data. We present a mapping of physical devices to health action plans that is device-agnostic and bridges this semantic gap. A key concept is the mapping of logical devices to primary health features that translates measurements to a meaningful health concept. We describe a prototype system implementing our mapping and providing lessons learned. The approach shows to be feasible to describe typical personal health action plans.

Touch gestures become steadily more important with the ongoing success of touch screen devices. Compared to traditional user interfaces, gestures have the potential to lower cognitive load and the need for visual attention. However, nowadays gestures are defined by designers and developers and it is questionable if these meet all user requirements. In this paper, we present two exploratory studies that investigate how users would use unistroke touch gestures for shortcut access to a mobile phone's key functionalities. We study the functions that users want to access, the preferred activators for gesture execution, and the shapes of the user-invented gestures. We found that most gestures trigger applications, letter-shaped gestures are preferred, and the gestures should be accessible from the lock screen, the wallpaper, and the notification bar. We conclude with a coherent, unambiguous set of gestures for the 20 most frequently accessed functions, which can inform the design of future gesture-controlled applications.

A recent study revealed that every fourth German adult drinks less than 1.5 litres a day. Insufficient fluid intake can cause headache, lack of energy and lightheadedness. Signals can be used to be reminded of drinking. However, these are often missed or even deactivated because they are too obvious. On the basis of a participatory design study, we designed the fashionable light bracelet WaterJewel as an awareness display and an unobtrusive reminder for a regular fluid intake. In a four-week 12-participant study, we explored the use of WaterJewel in daily life and how it compared to a prevalent mobile drinking reminder application. Our results show that with WaterJewel participants drank more in total, more often accomplished the daily drinking goal of 2 litres, drank more regularly, and drank more often prior to the reminder event than with the mobile application. Participants rated WaterJewel as very usable and appreciated its practical and discreet design.

In this paper we report on a participatory design study with young girls. Our goal was to create a mobile phone app to display the spatial proximity of friends in an abstract and privacy-aware manner. A group of 16 girls worked along the user-centred design process to create initial paper-based designs of an app that respects one's friends privacy while displaying their proximity to allow for spontaneous meetings or re-grouping after separation. Our participants created very promising results which we intend to implement and evaluate further against a broader audience.

Diary studies are often applied in HCI research to collect qualitative user impressions. Unfortunately, the period between creation of a diary entry and the later reflection can be too long, which leads to a limited currentness and contextuality. This eventually results in incomplete or misinterpreted data. In this paper we present Storyteller, a mobile application that allows a quick creation of diary entries and encourages users to reflect on these in-situ through a storytelling approach. We argue that this can lead to more accurate and substantial qualitative insights.

Travelers sometimes need to reach a destination in a given amount of time. However, today's navigation systems try to route users to the destination as fast as possible. In this paper, we present the concept of time-based pedestrian navigation. We use a map on a smartphone that highlights streets depending on whether they will lead to a destination in time. Our map also allows the users to choose between route alternatives during the walk.

Users nowadays increasingly use their smart phones to take photos and videos. Many of the users would like to create multimedia products such as physical photo books out of their photos or videos on the phone, however the screen of the phone is small for complicated editing and publishing process. In this demo paper we introduce an application that allows the user to automatically create a photo product out of his videos on the smart phone. The user can select one or several videos. The scenes of each video are detected using visual features, and for each scene a distinct good quality frame is selected. The videos are usually not very long and on average a video is 2 mins length in our dataset of users. We enrich the extracted representing frames with related photos from both the phone and from social networks like Facebook. We measure the similarity based on visual, metadata and social features. We apply a face recognition phase to enhance the accuracy of these features. At the end we compile the selected media content in an appealing photo product, that the user can edit later from any device. This process allows the user to make use of the phone videos to create appealing media products with very little effort that suits the small screen of the mobile phone.

Images and videos are easy to create by inexperienced users with intuitive devices like smartphones. We propose a system which enables users to extract panoramas from videos for the creation of collages which can be printed. Single frames used for panoramas are indexed on the basis of SURF features. As a result users can make a photo with the smartphone from a panorama within the printed collage or zoom into the digital version of a collage to select an area of interest and retrieve the related video using the SURF features index. Moreover users can pick a photo from a location where a video was previously recorded and retrieve a related video as well. Our approach supports the maintenance of a large number of videos.

With the rise of current smartphones, virtual keyboards for touchscreens became the dominant mobile text entry technique. We developed a typing game that records how users touch on the standard Android keyboard to investigate users' typing behaviour. 47,770,625 keystrokes from 72,945 installations have been collected by publishing the game. By visualizing the touch distribution we identified a systematic skew and derived a function that compensates this skew by shifting touch events. By updating the game we conduct an experiment that investigates the effect of shifting touch events, changing the keys' labels, and visualizing the touched position. Results based on 6,603,659 keystrokes and 13,013 installations show that visualizing the touched positions using a simple dot decreases the error rate of the Android keyboard by 18.3% but also decreases the speed by 5.2% with no positive effect on learnability. The Android keyboard outperforms the control condition but the constructed shift function further improves the performance by 2.2% and decreases the error rate by 9.1%. We argue that the shift function can improve existing keyboards at no costs.

In this paper, we report about a large-scale in-situ study of tactile feedback for pedestrian navigation systems. Recent advances in smartphone technology have enabled a number of interaction techniques for smartphone that use tactile feedback to deliver navigation information. The aim is to enable eyes-free usage and avoid distracting the user from the environment. Field studies where participants had to fulfill given navigation tasks, have found these techniques to be efficient and beneficial in terms of distraction. But it is not yet clear whether these findings will replicate in in-situ usage. We, therefore, developed a Google Maps-like navigation application that incorporates interaction techniques proposed in previous work. The application was published for free on the Android Market and so people were able to use it as a navigation system in their everyday life. The data collected through anonymous monitoring suggests that tactile feedback is successfully adopted in one third of all trips and has positive effects on the user's level of distraction.

We present PocketMenu, a menu optimized for non-visual, in-pocket interaction with menus on handheld devices with touch screens. By laying out menu items along the border of the touch screen its tactile features guide the interaction. Additional vibro-tactile feedback and speech allows identifying the individual menu items non-visually. In an experiment, we compared PocketMenu with iPhone's VoiceOver. Participants had to control an MP3 player while walking down a road with the device in the pocket. The results provide evidence that in the above context the PocketMenu outperforms VoiceOver in terms of completion time, selection errors, usability. Hence, it enables usage of touch screen apps in mobile contexts (e.g. walking, hiking, or skiing) and limited interaction spaces (e.g. device resting in a pocket).

Going on excursions to explore unfamiliar environments by bike is a popular activity in many places in this world. To investigate the nature of exploratory bicycle trips, we studied tourists on their excursions on a famous vacation island. We found that existing navigation systems are either not helpful or discourage exploration. We therefore propose Tacticycle, a conceptual prototype of a user interface for a bicycle navigation system. Relying on a minimal set of navigation cues, it helps staying oriented while supporting spontaneous navigation and exploration at the same time. In cooperation with a bike rental, we rented the Tacticycle prototype to tourists who took it on their actual excursions. The results show that they always felt oriented and encouraged to playfully explore the island, providing a rich, yet relaxed travel experience. On the basis of these findings, we argue that exploratory trips can be very well supported by providing minimal navigation cues only.

Facebook witnesses an explosion of the number of shared photos: With 100 million photo uploads a day it creates as much as a whole Flickr each two months in terms of volume. Facebook has also one of the healthiest platforms to support third party applications, many of which deal with photos and related events. While it is essential for many Facebook applications, until now there is no easy way to detect and link photos that are related to the same events, which are usually distributed between friends and albums. In this work, we introduce an approach that exploits Facebook features to link photos related to the same event. In the current situation where the EXIF header of photos is missing in Facebook, we extract visual-based, tagged areas-based, friendship-based and structure-based features. We evaluate each of these features and use the results in our approach. We introduce and evaluate a semi-supervised probabilistic approach that takes into account the evaluation of these features. In this approach we create a lookup table of the initialization values of our model variables and make it available for other Facebook applications or researchers to use. The evaluation of our approach showed promising results and it outperformed the other the baseline method of using the unsupervised EM algorithm in estimating the parameters of a Gaussian mixture model. We also give two examples of the applicability of this approach to help Facebook applications in better serving the user.

One of the bottlenecks in today's pedestrian navigation system is to communicate the navigation instructions in an efficient but non-distracting way. Previous work has suggested tactile feedback as solution, but it is not yet clear how it should be integrated into handheld navigation systems to improve efficiency and reduce distraction. In this paper we investigate augmenting and replacing a state of the art pedestrian navigation system with tactile navigation instructions. In a field study in a lively city centre 21 participants had to reach given destinations by the means of tactile, visual or multimodal navigation instructions. In the tactile and multimodal conditions, the handheld device created vibration patterns indicating the direction of the next waypoint. Like a sixth sense it constantly gave the user an idea of how the route continues. The results provide evidence that combining both modalities leads to more efficient navigation performance while using tactile feedback only reduces the user's distraction.

Mobile application stores such as Apple's App Store and Google's Android Market enable researchers to use App Stores as a platform for user studies. Because successful studies can require a large number of users researchers might need to attract a large audience. The right timing when releasing or updating apps can considerably increase the number of installations. Using a game that is published in the Android Market we analyze when people install games. Furthermore, we determine when developers deploy games in the Android Market. We combine data from 157,438 installations of the game and the observation of 24,647 published apps. Our results suggest that the best time to deploy a game in the Android Market is on Sunday evening GMT.

Touchscreens became the dominant input device for smartphones. Users' touch behaviour has been widely studied in lab studies with a relative low number of participants. In contrast, we published a game in the Android Market that records the touch behaviour when executing a controlled task to collect large amounts of touch events. Players' task is to simply touch circles appearing on the screen. Data from 91,731 installations has been collected and players produced 120,626,225 touch events. We determined the error rates for different target sizes and screen locations. The amount of data enabled us to show that touch positions are systematically skewed. A compensation function that shifts the users' touches to reduce the amount of errors is derived from the data and evaluated by publishing an update of the game. The independent-measures experiment with data from 12,201 installations and 15,326,444 touch events shows that the function reduces the error rate by 7.79%. We argue that such a compensation function could improve the touch performance of virtually every smartphone user.

Social networks such as Facebook witness an explosively growing number of shared photos. People enjoy taking photos of each other in public and private events, upload them, tag each other and continue commenting on each other's photos. These photos are considered to be great assets for many users who would like to create photo books from them, so that they can show their experience and special events to friends and family. However, finding the required photos is not an easy task, because they can be distributed over different friends and albums with different tags and annotations, and they can be of different importance to the user. In this paper we propose a software prototype which employs multimedia retrieval methods to allow an easy creation of photo books from social networks. In our system photos are first clustered to events which can potentially be distributed over the social network, and then selected based on their importance and finally distributed and laid out over the pages of a photo book. The functionalities of our system are implemented and deployed as web services and our presentation layer is a wizard-like Facebook application.

"Networking of Multimedia Women" event is a continuation of an on-going conversation in the multimedia research community and efforts by the ACM SIGMM to engage and promote female researchers in multimedia community, enable networking of junior and senior female researchers, and give insights towards successful professional careers based on examples.

No abstract available.

Photos are a special way to tell stories of our best memories and moments. The representation of those photos in appealing physical photo books is highly appreciated by many people. Today, many photos are shared via social networking sites, where people upload their photos and share their stories with their friends. The members of social networks comment on each other's photos, add tags or descriptions and upload new photos of the same events to their albums. While the media of different personal events are available on the social network, there is no easy way to collect and bundle them into a story and print this story as a photo book. We propose an approach to automatically detect media elements that match a query (where, when, what, who) in the user's social network and intelligently arrange and compose them into a printable photo book. We combine content analysis of text and images to automatically and semi-automatically select photos of a specific story. We calculate the probabilities of each two photos to belong to the same event using an Expectation-Maximization algorithm that we propose in order to be able to retrieve them easily when receiving the user queries, and we address the differences between our model and other models that use similar proposed algorithms. People's tags and the interaction between the users and the photos as well as other semantic information are exploited to select important photos that are suitable to create the photo book. The selected photos and derived semantics are then employed to automatically create an appealing layout for the photo book.

Tactile displays are an actively studied means to convey large amount of spatial information in the car. Their advantage compared to conventional car navigation systems is their ability to free the driver's visual and auditory senses. Previously the tactile displays were integrated into the seat of a car to present multiple direction information to the driver. However, in the commercial cars the seat is used to provide the vibro-tactile warning signals, so driver might not differentiate between navigation and warning information. Furthermore, the amount of information presented with tactile displays can cause significant cognitive workload, performance degradation and distraction to the driver. In this paper, we explore different methods of encoding multiple directions information with a tactile belt in the car. We compare the vibro-tactile presentation of spatial turn-by-turn information with a conventional car navigation system to measure cognitive workload, performance and distraction of the driver. We found that drivers showed better orientation performance on the tactile display than with the conventional car navigation system. At the same time there was no difference in cognitive workload, performance, and distraction. Thus, a tactile interface can be useful to present more information than simple left or right directions in high load driving conditions in which drivers are required to observe the traffic situation with their visual and auditory senses.

A group of friends visiting a crowded and noisy music festival is an example of a situation where knowing the location of other people is important, but where external factors, such as darkness or noise, can limit the ability to keep track of the others. By combining theories about situation awareness and cognitive processing we inferred that communicating information via the sense of touch is a promising approach in such situations. We therefore investigated how to present the location of several people using a tactile torso display. In particular we focused on encoding spatial distances in the tactile signals. We experimentally compared encoding spatial distances in the rhythm, duration, and intensity of a tactile signal. Our findings show that all parameters are suited to encode distances. None of it was clearly outperformed. We then embedded our tactile location encoding into a fast-paced 3D multiplayer game. In this game, team play and the awareness of the team members' locations are crucial for the success in the game. The results provides evidence that the locations of the team members could be processed effectively despite the game's high cognitive demands. In addition, the team equipped with the tactile display showed a better team play and a higher situation awareness.

Map navigation is often limited due to the inherent size re-strictions of mobile devices ’ displays. Using a magic lens to interact with physical objects has been proposed as a way to reduce this limitation. The dynamic peephole interface is an alternative approach where a device is moved across a virtual surface. In this paper we study the effect of an additional visualization of objects beyond the screen on magic lens and dynamic peephole interfaces. In the conducted experiment the participants had to select points of interest shown on a map. We show that an additional visualization of off-screen objects decreases the task completion time and reduces the perceived task load. The advantage of an off-screen visual-ization is much higher than the difference between using a magic lens instead of a dynamic peephole interface.

The introduction of publicly available application stores for mobile devices enables to publish research prototypes to a wide audience. This distribution channel can be used to conduct studies with participants from all over the world and diverse backgrounds. We report from a study that compares three visualization techniques for off-screen objects on digital maps. Usage data from 362 persons was collected and 105 persons completed an interactive tutorial. Significant differences between the three conditions were found. The results support previous findings but we conjecture that the results are affected by unintended influences.

Pedestrian navigation systems are becoming popular but the currently dominant audio-visual interaction can have drawbacks. Tactile feedback is studied as a solution, but currently only available as research prototypes. With the PocketNavigator we propose a demonstrator that adds tactile feedback to a simple but robust map-based navigation system that runs on any Android Smartphone. Users can leave the device in the pocket, while being guided non-visually through vibration cues. Like a compass we "point at" the next waypoint by encoding its direction and distance in vibration patterns. As an advantage over previous approaches it allows giving continuous feedback instead of isolated turning instructions and it can be realized without custom-built tactile displays. Preliminary results from a field study show that pedestrian can effectively use this Tactile Compass to reach a destination without turn-by-turn instructions. Integrated into the PocketNavigator we can now deploy it at the Android Market to evaluate the Tactile Compass with a wide range of users.

An emerging technology for tourism information systems is mobile Augmented Reality using the position and orientation sensors of recent smartphones. State-of-the-art mobile Augmented Reality application accompanies the Augmented Reality visualization with a small mini-map to provide an overview of nearby points of interest (POIs). In this paper we develop an alternative visualization for nearby POIs based on off-screen visualization techniques for digital maps. The off-screen visualization uses arrows directly embedded into the Augmented Reality scene which point at the POIs. In the conducted study 26 participants explored nearby POIs and had to interpret their position. We show that participants are faster and can interpret the position of POIs more precisely with the developed visualization technique.

The ACM SIGMM International Workshop on Social Media (WSM'10) is the second workshop held in conjunction with the ACM International Multimedia Conference (MM'10) at Firenze, Italy, 2010. This workshop provides a forum for researchers and practitioners from all over the world to share information on their latest investigations on social media analysis, exploration, search, mining, and emerging new social media applications.

For many people web blogs are the preferred means to document important moments of their lifes, e.g. a holiday trip or the year abroad. Such blogs contain photos and textual descriptions of events in a well-structured form. However, while being a perfect means to share such important moments with friends and family, blogs remain digital and thus do not provide the valuable experience of a physical souvenir of the documented event, such as a photo book. In this paper we therefore propose a solution to combine the advantages of both web blogs and printed photo books. We bridge the gap between the digital and physical world by providing a system to automatically transform a blog into a photo book. For this we employ our system for automatic page layout following aesthetic principles. The structure of the blog is reflected in the overall layout of the photo book. We also enrich the resulting photo book with additional content from the web by employing links and location information present in the blog entries. The result is a physical counterpart to the original blog in a nice layout. Our approach is implemented as a web-based rich media application.

Music is a fundamental part of most cultures. Controlling music playback has commonly been used to demonstrate new interaction techniques and algorithm. In particular, controlling music playback has been used to demonstrate and evaluate gesture recognition algorithms. Previous work, however, used gestures that have been defined based on intuition, the developers' preferences, and the respective algorithm's capabilities. In this paper we propose a refined process for deriving gestures from constant user feedback. Along this process a set of free-hand gestures for controlling music playback is developed. The situational context is analyzed to shape the usage scenario and derive an initial set of necessary functions. In a successive user study the set of functions is validated. Furthermore, proposals for gestures are collected from the participants for each function. Two gesture sets containing static and dynamic gestures are derived and analyzed in a comparative evaluation. The evaluation shows that we developed an appropriate set of free-hand gestures for music playback. Our results indicate that the proposed process, that includes validation of each design decision, improves the final results.

Location information on the Web is a precious asset for a multitude of applications and is becoming an increasingly important dimension in Web search. Even though more and more Web pages carry location information, they form only a small share of all pages and are scattered over the Web. To efficiently find and index location-related Web content, we propose an efficient crawling strategy that retrieves precisely those pages that are geospatially relevant while minimizing the amount of the non-spatially-relevant pages within the crawled pages. We propose to address this challenge by ex-panding the technique of focused crawling to exploit location references on Web pages to specifically retrieve geospatial topics on the Web. In this paper, we describe the design and development of a focused crawler with an adaptive geospa-tial focus that efficiently retrieves and identifies location-relevant documents on the Web. Drawing from geospatial features of both Web pages and the link graph, a crawl strat-egy based on Bayesian classifiers prioritizes promising links and pages, leading to a faster coverage of the desired geospa-tial topic as a means for fast creation of precise geospatial Web indexes. We present evaluations of the system’s perfor-mance and share our findings on the geospatial Web graph and the distribution of location references on the Web.

Paper maps are a proven means for navigating in unfamiliar environments, however, they do not prevent people from getting lost or taking unwanted detours. A well-known issue is interpreting the map's geocentric content, which is known to become prone to errors when the map is not aligned to the environment. In this paper we report our investigation of providing a cue about the destination's location from an egocentric perspective in order to improve the interpretation of the map. We used a vibrotactile belt to continuously indicate a destination's direction relative to the user's orientation. In an outdoor field study we compared the performance of map-based navigation with and without the added tactile cue. We found evidence that people take shorter routes, consult the map less often, and were less often disoriented with the tactile cue. Furthermore, females found the tactile cue more useful and used it more often.

Cycling is a common leisure time sports in touristic regions. For us it was the question how tourists actually find their paths in the area and what kind of navigation aids might be helpful to them. In a requirements study on a touristic island we learned that tourists rather explore the environment spontaneously than efficiently navigating from on place to another such as the beach or the light house, and just cycle on without much map or navigation aid. While exploring the area, the cyclists however, sometimes lose their orientation which they compensate for by accepting detours. We designed and developed an orientation aid, Tacticycle that does not influence the cycling experience but improve the orientation and awareness of the overall direction. In order to ensure the cyclists' safety two vibrotactile actuators are used to indicate directions and announce the presence of interesting places. In two field studies we showed that despite the accuracy of the indicated direction being rather coarse, the tactile user interface allows cyclists to reach a presented destination easily. The visitor of the demo can experience a virtual cycling tour supported by the Tacticycle demonstrator.

The ACM SIGMM International Workshop on Social Media (WSM'09) is the first workshop held in conjunction with the ACM International Multimedia Conference (MM'09) at Bejing, P.R. China, 2009. This workshop provides a forum for researchers and practitioners from all over the world to share information on their latest investigations on social media analysis, exploration, search, mining, and emerging new social media applications.

In our everyday life we often see objects or persons and are aware that there are related digital services such as an online ticket service when seeing a poster advertising a concert. Currently it is a rather time consuming activity to find the related information. Using our Contextual Bookmark system a user can define a snapshot with her mobile phone consisting of a picture, time stamp and location. Such a bookmark can then be stored on the mobile phone, exchanged with friends and in particular be used to access related videos, web pages, and other services. This helps the user to bridge the gap between the virtual and the real world in order to use related services. Combining content and context analysis objects are recognized without any visual markers or electronic tags. We would like to demonstrate our system based on a nomadic usage scenario in which a person defines a Contextual Bookmark of a movie trailer, buys the corresponding movie, plays the movie on a TV, and exchanges the bookmark with a friend.

The sharing of photos with others, friends and family, has become even more popular with digital photography and Internet applications such as email or Web albums. At the same time, the physical touch of printed photos is still appreciated and customers use different services to print their photos on post cards, calendars or photobooks, often to give them as a present or to create a physical souvenir. Once printed, however, the sharing of photos with others becomes difficult as there is no link back from the now physical item to its digital counterpart. With Bookmarkr, we developed a system that employs a mobile camera phone to bridge the gap between the printed photo and its digital counterpart. The user takes an image of a photo in a photobook with the mobile phone's camera. The image is transmitted to a photobook server, which employs image analysis techniques to retrieve the corresponding photo. The photo is sent back to the user and establishes the digital-physical match. Bookmarkr allows the user to interact with printed photos in a similar way as interacting with digital photos by using a point-and-shoot metaphor. Our performance evaluation shows that the system is able to return the correct photo in up to 99% of all cases. A conducted user study revealed that the designed interaction is suitable for the participants and their printed photobooks.

In many applications today user interaction is moving away from mouse and pens and is becoming pervasive and much more physical and tangible. New emerging interaction technologies allow developing and experimenting with new interaction methods on the long way to providing intuitive human computer interaction. In this paper, we aim at recognizing gestures to interact with an application and present the design and evaluation of our sensor-based gesture recognition. As input device we employ the Wii-controller (Wiimote) which recently gained much attention world wide. We use the Wiimote's acceleration sensor independent of the gaming console for gesture recognition. The system allows the training of arbitrary gestures by users which can then be recalled for interacting with systems like photo browsing on a home TV. The developed library exploits Wii-sensor data and employs a hidden Markov model for training and recognizing user-chosen gestures. Our evaluation shows that we can already recognize gestures with a small number of training samples. In addition to the gesture recognition we also present our experiences with the Wii-controller and the implementation of the gesture recognition. The system forms the basis for our ongoing work on multimodal intuitive media browsing and are available to other researchers in the field.

The World Wide Web has become the world's largest networked information resource, but references to geographical locations remain unstructured and typically implicit in nature. This lack of explicit spatial knowledge within the Web makes it difficult to service user needs for location-specific information. At present, spatial knowledge is hidden in many small information fragments such as addresses on Web pages, annotated photos with GPS co-ordinates, geographic mapping applications, and geotags in user-generated content. Several emerging formats that primarily or secondarily include location metadata, like GeoRSS, KML, and microformats, aim to improve this state of affairs. However, the question remains how to extract, index, mine, find, view, mashup, and exploit Web content using its location semantics. This work-shop brings together researchers from academia and industry labs to discuss and present the latest results and trends in all facets of the relationships between location concepts and Web information.

Rich media data, such as video, imagery, music, and gaming, do no longer play just a supporting role on the World Wide Web to text data. Thanks to Web 2.0, rich media is the primary content on sites such as Flickr, PicasaWeb, YouTube, and QQ. Because of massive user generated content, the volume of rich media being transmitted on the Internet has surpassed that of text. It is vital to properly manage these data to ensure efficient bandwidth utilization, to support effective indexing and search, and to safeguard copyrights (just to name a few). This panel invites both researchers and practitioners to discuss the challenges of Web-scale media-data management. In particular, the panelists will address issues such as leveraging Rich Media and Web 2.0, indexing, search, and scalability.

Photos are often a means to remember personal events, and the creation of photo albums is the attempt to preserve our memories in a nice book. For a long time people have been creating such photo albums on the basis of prints from analog photos arranged in an album book with scissors and glue and annotated with comments and captions - a tedious task which in these days is getting support by authoring tools and digitally mastered photo books. Relying on the content of others such as printed travel guides, news papers, leaflets, but also friends and family the personal content often has been enriched, enhanced, and completed. This is the starting point of our work: with digital photography and the increasing amount of content-based and contextual metadata of personal photos we can now use this metadata to actually support the targeted and semi-automatic inclusion of interesting, related information from content of others, e.g., from Web 2.0 communities, and offer and add it at the right spot in the personal album. In this paper, we show how photo album creation can benefit from leveraging information learned from many users in regard of the album's content, structure, and semantics.

The combination of the emerging digital video broadcasting-handheld (DVB-H) standard with cellular communication like UMTS produces a hybrid network with enormous potential for mobile multimedia applications. In order to optimize the performance of hybrid networks, the characteristics of different individual networks have to be considered. Our prototypical hybrid network infrastructure employs smart access management for an optimal usage of both broadcast and point-to-point network. Our demonstrator-"night scene live", a multimedia event portal-is an excellent example of an application exploiting the potential of future hybrid networks

In recent years, many highly sophisticated multimedia authoring tools have been developed. Up to today, these system's integration of the targeted user context, however, is limited. With our Context-aware Smart Multimedia Authoring Tool (xSMART) we developed a semi-automatic authoring tool that integrates the targeted user context into the different authoring steps and exploits this context to guide the author through the content authoring process. The design of xSMART allows that it can be extended and customized to the requirements of a specific domain by domain-specific wizards. These wizards realize the user interface that meets best the domain-specific requirements and effectively supports the domain experts in creating their content targeted at a specific user context.

In this paper, we present the Media Gallery, a MHP-based interactive multimedia application on digital TV. This application allows customers to view and order their digital photos and to order physical prints and fun products from these digital photos directly from TV. The Media Gallery opens a new distribution channel and market opportunity for the photo finisher and a platform to comfortably view and order their digital images directly on their TV.

Users of multimedia applications today are equipped with a variety of different (mobile) devices that each come with different operating systems, memory and CPU capabilities, network connections, and also different software such as multimedia players. To be able to efficiently deliver appealing multimedia presentations to all the users, we need to overcome the last mile in multimedia presentation delivery and meet the different requirements at the end user’s site. Consequently, one needs to provide multi-channel multimedia presentation generation such that all different users can get and use it in their individual device configuration. With our approach, we aim at developing an abstract multimedia content model that embeds the central characteristics of today’s multimedia presentation formats: the definition of the temporal and spatial layout as well as the interaction possibilities. The abstract model allows to be easily transformed to different multimedia presentation formats on different devices and by this serve different output channels. We present our abstract multimedia model and transformation process that allows to compose and to generate suitable multimedia presentations for each different channel such as a SMIL 2.0 presentation created for rendering on a PC or a SVG Tiny presentation designed for a mobile device. With our implementation, application developers can efficiently realize on-the-fly multichannel generation of multimedia content.

No abstract available.

No abstract available.

The latest achievements in the field of mobile networks and ubiquitous computing enable the integration and combination of technologies like Internet, Java, and multimedia in a new kind of application that employs distribution, wireless networking, localisation, and movement---mobile location-aware multimedia games. The approach presented is an innovative re-invention of a paper chase/scavenger hunt as a mobile location-aware game. The video demonstration illustrates the technical foundation and the system design of the mobile game. We also show the fun and the action of the game following some students when they play the game on our university campus.

Mobile applications such as mobile tourist guides that provide tourists with location-based information today mostly aim to adapt the multimedia content to the different end user devices. More and more, these applications also exploit positioning information like GPS to guide the user on the trip. What is still lacking, however, is a personalization of the content to the interests and preferences of the individual tourist and the characteristics of the used end device. However, such a personalization increases the application's complexity since every individual alternatives have to be considered and implemented. To provide substantial support for the development of personalized (mobile) multimedia applications, we developed a domain independent software framework for an efficient and cost-effective development of personalized mobile multimedia applications. We illustrate the framework in the specific domain of personalized mobile tourist information.

Existing multimedia streaming technologies offer no specific support for user interaction like jumping to bookmarks in a video, or switching to reverse play. When the users, e.g., jump to a bookmark, the player requests frames for the new presentation point from the server and resumes playing only when the data has arrived. Our solution for this problem is the client prefetching the buffering strategy, MPEG-L/MRP, that ensures that the frames which are needed for a response to a possible user interaction are already in the client's buffer, which leads to qucik and smooth reaction to user interactions. In case of variable bandwidth, our MPEG-1 streaming approach selects only a subset of all frames to be fetched from the server and supports a smooth presentation at a reduced frame rate with correct timelines.The technical demonstration shows the interactive streaming of MPEG-videos and illustrates our buffering and prefetching strategy.

Advanced multimedia applications require adequate support for the modeling of multimedia content by multimedia document models. More and more this support calls for not only the adequate modeling of the temporal and spatial course of a multimedia presentation and its interactions, but also for the partial reuse of multimedia documents and adaptation to a given user context. However, our thorough investigation of existing standards for multimedia document models such as HTML, MHEG, SMIL, and HyTime leads to us the conclusion that these standard models do not provide sufficient modeling support for reuse and adaptation. Therefore, we propose a new approach for the modeling of adaptable and reusable multimedia content, the Z/sub Y/X model. The model offers primitives that provide-beyond the more or less common primitives for temporal, spatial, and interaction modeling-a variform support for reuse of structure and layout of document fragments and for the adaptation of the content and its presentation to the user context. We present the model in detail and illustrate the application and effectiveness of these concepts by samples taken from our Cardio-OP application in the domain of cardiac surgery. With the Z/sub Y/X model, we developed a comprehensive means for advanced multimedia content creation: support for template-driven authoring of multimedia content and support for flexible, dynamic composition of multimedia documents customized to the user's local context and needs. The approach significantly impacts and supports the authoring process in terms of methodology and economic aspects.

Adaptation techniques for multimedia presentations are mainly concerned with switching between different qualities of single media elements to reduce the data volume and by this to adapt to limited presentation resources. This kind of adaptation, however, is limited to an inherent lower bound, i.e., the lowest acceptable technical quality of the respective media type. To overcome this limitation, we propose cross-media adaptation in which the presentation alternatives can be media elements of different media type, even different fragments. Thereby, the alternatives can extremely vary in media type and data volume and this enormously widens the possibilities to efficiently adapt to the current presentation resources. However, the adapted presentation must still convey the same content as the original one, hence, the substitution of media elements and fragments must preserve the presentation semantics. Therefore, our cross-media adaptation strategy provides models for the automatic augmentation of multimedia documents by semantically equivalent presentation alternatives. Additionally, during presentation, substitution models enforce a semantically correct information flow in case of dynamic adaptation to varying presentation resources. The cross-media adaptation strategy allows for flexible reuse of multimedia content in many different environments and, at the same time, maintains a semantically correct information flow of the presentation.