Personal audio technologies empower individuals to manage their own auditory environment, affording control over both digital and real-world sounds. However, this control comes at a potential cost to social interaction, awareness of surroundings, and safety. This paper explores and investigates leveraging personal audio technologies as mediators in establishing personal audio spaces in homes. Our research methodology consisted of two key phases. Initially, a series of design workshops involving 16 participants were conducted to explore potential enhancements to everyday listening situations through technology. Subsequently, a within-subjects mixed-method study with 18 participants was undertaken to investigate the user experience of employing personal audio technologies to create a personalised audio space. The findings provide insights into future opportunities for listening practices, audio content, interpersonal listening, enhancing listening experiences as well as experiential components. Drawing from our results, we engage in a discussion on the potential manifestations of personal audio spaces, while also addressing current technological limitations and suggesting avenues for future research directions.

Sound zone technology enables multiple people to have personal and shared listening experiences without disturbing each other. Methods for constructing sound zones have now matured enough to allow installations outside of experimental laboratories, making it essential for further development to conduct empirical studies about how people adopt, use, and interact with sound zones in, e.g., domestic settings. To that end, we conducted a four-week field study with a sound zone system in five households. Through an inductive reflexive thematic analysis, we identify three themes relating to 1) experiencing sound zones in everyday life, 2) sound zone usage patterns in households, and 3) interacting with sound zones. Based on these themes, we discuss how sound zones can be used to manage sound in homes in new ways to allow for better social coexistence and listening experiences. We present four directions for future HCI research and interaction design to comply with user needs and considerations when using this novel technology.

Sound zone technology allows multiple simultaneous sound experiences for multiple people in the same room without interference. However, given the inherent invisible and intangible nature of sound zones, it is unclear how to communicate the position and size of sound zones to users. This paper compares two visualisation techniques; absolute visualisation, relational visualisation, as well as a baseline condition without visualisations. In a within-subject experiment (N = 33), we evaluated these techniques for effectiveness and efficiency across four representative tasks. Our findings show that the absolute and relational visualisation techniques increase effectiveness in multi-user tasks but not in single-user tasks. The efficiency for all tasks was improved using visualisations. We discuss the potential of visualisations for sound zones and highlight future research opportunities for sound zone interaction.

In this paper, we investigate the use of shape-change for interaction with sound zones. A core challenge to designing interaction with sound zone systems is to support users’ understanding of the unique spatial properties of sound zones. Shape-changing interfaces present new opportunities for addressing this. We present a structured investigation into this. We leveraged the knowledge of 12 sound experts to define a set of basic shapes and movements. Then, we constructed a prototype and conducted an elicitation study with 17 novice users, investigating the experience of these shapes and movements. Our findings show that physical visualizations of sound zones can be useful in supporting users’ experience of sound zones. We present a framework of 4 basic pattern categories that prompt different sound zone experiences and outline further research directions for shape-change in supporting sound zone interaction.

Commercialised voice user interface devices for the home, like Amazon Echo, Google Home, and Apple HomePod, with integrated digital personal assistants have rapidly grown in popularity. These devices embody intelligent software agents that support users in their everyday life through easy and intuitive conversational interactions. While their use in everyday activities is largely unexplored, the proliferation in home use presents a valuable opportunity to add to understanding around the use of in-home digital personal assistants. In this paper, we investigate their home use in a broad context to learn more about people’s experiences, attitudes, interactions and expectations with these devices contributing new insights to current knowledge around this use. Applying the digital ethnography method, we collected 3542 reviews and comments about Amazon Echo, Google Home, and Apple HomePod on Amazon, eBay, and Reddit. Six main themes and 29 categories were derived through filtering, thematic analysis and affinity diagramming. These findings constitute a conceptual framework characterising the current landscape of home use of digital personal assistants. Additionally, we identify and discuss unique issues discovered around the invisible interface, interactive freedom, and creative appropriation. We use our findings to propose implications for interaction design of DPAs for home use.

Digital personal assistants (DPAs) have recently grown in popularity because they are both a commercially available new technology and reasonably affordable to the average household. This opens opportunities for new ways to assist people in everyday activities in their homes through voice-interaction. Physical activity has significant health benefits, and yet globally, 1 in 4 adults are not active enough. To address this, we investigate the persuasive potential of DPAs in increasing people’s physical activity at home. We conducted a study with 48 participants to understand the effect of applying three of Fogg’s persuasive principles to the design of a DPA exercise programme: Suggestion, Virtual Reward, and Praise. Our findings show that DPAs have the potential, within their current technical and reactive capabilities, to persuade people to increase their physical activity at home, using Suggestion to encourage physical effort, Virtual Reward to encourage endurance, and Praise to create reassurance for beginners. Based on this, we offer three alternate perspectives for developing persuasive DPAs. We also discuss limitations of the study and suggest future research directions around using persuasion with DPAs.

Several smartwatch vendors have over the past years entered the market with a large range of devices that differ in the design qualities they offer. In this paper, we focus on design qualities that are either perceived, descriptive or physical, and we investigate which of them may lead people to prefer particular smartwatches over others. To do so we conducted a laboratory study with 93 potential smartwatch users and a trained panel study with 8 participants. Results were analysed through a multivariate statistical technique called Preference Mapping. The advantage of this technique is that it can relate a large number of design qualities to users’ preferences. Our findings show that participants can be divided into four groups with homogenous preferences, each emphasising a unique combination of design qualities. For example, some groups emphasised device shape, while others prioritised expensiveness for their preferred smartwatch. We conclude with implications of our work on practice and research.

Going beyond dyadic (one-to-one) interaction has been increasingly explored in HRI. Yet we lack a comprehensive view on non-dyadic interaction research in HRI. To map out 15 years of works investigating non-dyadic interaction, and thereby identifying the trend of the field and future research areas, we performed a literature review containing all 164 publications (2006-2020) from the HRI conference investigating non-dyadic interaction. Our approach is inspired by the 4C framework, an interaction framework focusing on understanding and categorising different types of interaction between humans and digital artefacts. The 4C framework consists of eight interaction principles for multi-user/multi-artefact interaction categorised into four broader themes. We modified the 4C framework to increase applicability and relevance in the context of non-dyadic human-robot interaction. We identify an increasing tendency towards non-dyadic research (36% in 2020), as well as a focus on simultaneous studies (85% from 2006-2020) over sequential. We also articulate seven interaction principles utilised in non-dyadic HRI and provide specific examples. Last, based on our findings, we discuss several salient points of non-dyadic HRI, the applicability of the modified 4C framework to HRI and potential future topics of interest as well as open-questions for non-dyadic research.

Domestic robots such as vacuum cleaners or lawnmowers are becoming popular consumer products in private homes, but while current HCI research on domestic robots has highlighted for example personalisation, long-term effects, or design guidelines, little attention has been paid to automation. To address this, we conducted a qualitative study with 24 participants in private households using interviews, contextual technology tours, and robot deployment. Through thematic analysis we identified three themes related to 1) work routines and automation, 2) domestic robot automation and the physical environment, as well as 3) interaction and breakdown intervention. We present an empirical understanding of how task automation using domestic robots can be implemented in the home. Lastly, we discuss our findings in relation to existing literature and highlight three opportunities for improved task automation using domestic robots for future research.

Routines are an important element of day-to-day work life, supporting people in structuring their day around required tasks. Effectively managing these routines is, however, experienced as challenging by many – an issue further amplified by the current work from home lockdown measures. In this paper we present Rainmaker, a tangible device to support people in their working life in the context of their own homes. We evaluate and iterate on our prototype through two qualitative studies, spanning respectively three days (N = 11) and 15 days (N = 2). Our results highlight the perceived advantages of the use of a primarily physical rather than digital tool for work support, allowing users to stay focused on their tasks and reflect on their work achievements. We present lessons for future work in this area and publicly release the software and hardware used in the construction of Rainmaker.

Mobile devices are fast becoming an integral part of family life. While mobile technology provides constant connectivity to a world outside the home, it inevitably disrupts family dynamics and the social notion of being together. In this paper, we explore "non-use" of mobile technology in a family setting. To do this, we designed the Pup-Lock provotype, a design provocation intended to challenge established expectations and practices around mobile device use at home. We report on a five-week in-depth study of using Pup-Lock with three families reflecting on their mobile device usage and their experience of non-use. Our findings illustrate how mobile use shapes social expectations and how over-use creates tensions in families. We contribute by showing how provoking non-use through design results in desirable and meaningful ways to increase family interaction. We discuss implications of designing for non-use to challenge established domestic practices around technology use.

Human--building interaction (HBI) is converging the fields of architecture and interaction design, leading to new and interesting tensions in perspectives and methodological approaches. One such tension is related to temporal constraints. Architecture and interaction design typically produce outcomes with very different lifetime expectancies and, predominantly, use methods with very different pace. As an example, fast, iterative approaches of contemporary interaction design, consisting of frequent updates and redesigns, contrasts with much slower, plan-driven and long-term vision driven approaches within architecture. One question emerging from this tension is how to meaningfully combine perspectives and approaches. One suggestion, among others, has been that interaction design methods such as participatory design can be used to heighten the involvement of inhabitants and other stakeholders in continuous adaptations of the buildings they inhabit. While an interesting proposal, we believe that methodological considerations only partly address the complexity of the tension at play from the different lifetime expectancies of buildings and interactive computer systems. Unfolding this complexity further, we therefore propose a framework of temporal constraints at three levels of abstraction: (1) rationale, (2) method, and (3) outcome. Inspired by previous work, we discuss temporal constraints in HBI at these levels. We argue that designing for HBI requires an understanding of temporally constrained design conventions that apply meaningfully to both the short term and long term.

Within sustainable HCI research, we have witnessed a growing interest in studying interaction designs that support households to 'shift' energy usage to times when it is sustainably favourable. In this paper, we investigate shifting through a purposely provocative and scripted design, which challenges the idea that renewable electricity is an always-available resource for households to consume. To do so, we made electricity for washing laundry either free or not available. We conducted a detailed qualitative study with four families that experienced our intervention for a month. We present five themes that illustrate how families adapted, reflected, and formed new routines and expectations related to washing practices. We discuss the broader implications of combining scripting and provocation as a means to intervene, disrupt and understand energy consuming practices within the home.

In this paper, we present an exploratory study of hygge as a low-energy design vision for the smart home. Hygge is a Danish concept that embodies aesthetic experiences related to conviviality, often shaped by orchestrating atmospheres through low-level lighting. To explore this vision, we probe two Australian households that already live with smart home lighting technology. We report on household reflections of embedding hygge into everyday life. We conclude by outlining future directions for exploring desirable and sus¬tainable smart home visions.

Research has shown that desirable designs shape the use and experiences people have when interacting with technology. Nevertheless, how desirability influences energy consumption is often overlooked, particularly in HCI studies evaluating the sustainability benefits of smart home technology. In this paper, we present a qualitative study with 23 Australian households who reflect on their experiences of living with smart home devices. Drawing on Nelson and Stolterman's concept of desiderata we develop a typology of householders' desires for the smart home and their energy implications. We structure these desires as three smart home personas: the helper, optimiser and hedonist, which align with desiderata's three approaches to desire (reason, ethics and aesthetics). We use these insights to discuss how desirability can be used within HCI for steering design of the smart home towards sustainability.

Ride-sharing can potentially address transportation challenges such as traffic congestion and air pollution by letting drivers share their cars unused capacity with a number of passengers. However, even though multiple ride-sharing services exist and HCI research has investigated various aspects of their use, we still have limited knowledge on how passengers use ride-sharing services to plan their trips. In this paper, we study how passengers use existing services to support the activity of planning a trip. We report from a qualitative study where we participated in 5 rides and conducted interviews with 19 passengers about their use and opinions towards ride-sharing services. We found that planning a ride involves comparing individual preferences across a number of services which enabled participants to support finding a trip and handle challenges such as privacy and trust. Further, we discuss these findings and their implications for future HCI research in ride-sharing.

Since the emergence of video computer games in the early 70's, the concept of "cheating" has been a hot issue in video gaming research. Adding mobility and location-based capabilities to computer games introduces a whole new set of behaviours, motivations and justifications that challenge gaming communities to reconsider what constitutes "cheating", and what is simply an acceptable extension of game play. Using the specific case of Pokémon GO, we investigate players' perceptions on cheating in this mobile location-based game. In our research, we identified 10 ways that players circumvent the rules of Pokémon GO. Through analysis of online forums, field observations, interviews, and a focus group with local players, we realised that players' attitudes vary as to what constitutes "cheating", and whether playing outside the rules is acceptable. We found players "cheat" to enhance game experience, to compensate for limitations in the game's design, or to keep up with other cheaters. While this has been observed in online gaming before, our study contributes to research by relating these specifically to the game's mobile location-based nature. We offer implications for design of location-based games.

Shifting is an energy-conserving interaction strategy for moving energy consumption to times where it is sustainably favorable. This interaction strategy is attracting increasing interest within sustainable HCI studies. While most of these consider how interactive technology can change household behavior, only a few report on how shifting is experienced in everyday life when assisted by automation. In this study, we investigate an interactive technology that assists households to shift electricity consumption to times when electricity is cheap or more sustainable. Our study was conducted as a long-term field deployment for 6--18 months with eight households, each living with an interactive prototype that shifts running times for a heat pump within user-defined boundaries. Our findings show that managing heat pumps toward assisted shifting was well-received by all households because it was a convenient way to shift electricity consumption. Shifting electricity use facilitated price savings of 6.8–16.9%. Nevertheless, our findings also reveal a conflict between the system design, and how householders actually interact with their heating system and experience assisted shifting. Based on the eight households’ experiences, we present three overall themes of convenience, control, and complexity that each describes different aspects of long-term real-life use of automatic technology assisting households to shift electricity use. We discuss the broader implications of these findings and the role of design and future sustainability technology in everyday life.

Recently within HCI, design approaches have appeared, which deviate from traditional ones. Among them critical design introduces deliberate provocations in order to challenge established perceptions and practices. We have engaged ourselves with this design approach out of interest in understanding how to use provocation in research through design. Towards this end, we report on a field study with four families that used an aesthetically, functionally and conceptually provocative future probe. The purpose of the probe was to challenge existing energy consuming practices through provocation and make its users reflect on them. The paper describes how all three provocative aspects were addressed, and our findings demonstrate how they were experienced in the real world, and how they impacted our research through design approach. We conclude by presenting reflections on how to design provocations, and reflections on the impact of provocations for research through design in general.

There is a growing interest in HCI research to explore cross-device interaction, giving rise to an interest in different approaches facilitating interaction between handheld devices and large displays. Contributing to this, we have investigated the use of four existing approaches combining touch and mid-air gestures, pinching, swiping, swinging and flicking. We look specifically at their relative efficiency, effectiveness and accuracy in bi-directional interaction between a smartphone and large display in a point-click context. We report findings from two user studies, which show that swiping is both most effective, fastest and most accurate, closely followed by swinging. What these two approaches have in common is the ability to keep the pointer steady on the large display, unaffected by concurrent gestures or body movements used to complete the interaction, suggesting that this is an important factor for designing effective cross-device interaction with large displays.

The amount of interactive digital technology in cars is increasing rapidly, and many new cars are shipped with connectivity. As a result, a new platform has emerged that holds potentials to facilitate many new and different interactions, both inside and outside the car. Within the area of HCI for cars, the focus has predominantly been on interactions with in-vehicle systems and applications of technology that is enabled through connectivity. However, we still lack in-depth empirical studies that provide details of the connected car, its use, opinions towards it, and how it integrates into people's everyday lives. We report from a qualitative study of 13 households with connected electric cars. We present our findings in 3 themes of interaction through connectivity, updating and upgrading car software, and security and privacy. We further discuss our findings in 3 themes that might inform and inspire further mobile HCI research with the connected car.

Recently a number of studies appeared that operationalised coolness and explored its relation to digital products. Literature suggests that perceived coolness is another factor of user experience, and this adds to an existing explosion of dimensions related to aesthetics, hedonic quality, pragmatic quality, attractiveness, etc. A critical challenge highlighted in prior research is to study the relationships among those factors and so far, no studies have empirically examined the relationship between coolness and other established user experience factors. In this paper, we address this challenge by presenting two studies one that focuses on factors from two cool questionnaires, and one that compares them against existing User eXperience (UX) factors. Our findings show that factors from the two cool questionnaires converge and they also converge to existing, established UX factors. Thus, 11 distinct cool and UX factors converge into 5 for the case of mobile devices. Our findings are important for researchers, as we demonstrate through a validated model that coolness is part of UX research, as well as for practitioners, by developing a questionnaire that can reliably measure both perceived inner and outer coolness as well as the overall coolness judgement based on 5 factors and 21 items.

In the past decade, there has been increasing interest in studying tabletop technologies in HCI. Using the Gartners Hype Cycle as an analytical framework, this article presents developments in tabletop research within the last decade. The objective is to determine the level of maturity of tabletop technologies with respect to the research foci and the extent to which tabletops have shown their worth in real world settings. We identify less studied topics in the current body of literature with the primary aim of evoking further discussions of the current and future research challenges. We analyzed 542 research publications and categorized these according to eight types of research foci. Findings show that only 3% of all studies are conducted in natural settings, i.e. there is a clear tendency to emphasize laboratory evaluations of tabletop technology. Also, very few studies demonstrate relative benefits of tabletops over other technologies in collaborative settings (1%). We argue for a need to increase emphasis on understanding real-world use and impact rather than developing new tabletop technologies.

Discovering activities in the city around you can be difficult with traditional search engines unless you know what you are looking for. Searching for inspiration on things to do requires a more open-ended and explorative approach. We introduce transitory search as a dynamic way of uncovering information about activities in the city around you that allows the user to start from a vague idea of what they are interested in, and iteratively modify their search using slider continuums to discover best-fit results. We present the design of a smartphone app exemplifying the idea of transitory search and give results from a lab evaluation and a 4-week field deployment involving 15 people in two different cities. Our findings indicate that transitory search on a mobile device both supports discovering activities in the city and more interestingly helps users reflect on and shape their preferences in situ. We also found that ambiguous slider continuums work well as people happily form and refine individual interpretations of them.

Coolness has recently started to be explored as a design goal for interactive products from practitioners as well as researchers within human–computer interaction (HCI), but there is still a need to further operationalise the concept and explore how we can measure it. Our contribution in this paper is the COOL questionnaire. We based the creation of the questionnaire on literature suggesting that perceived coolness is decomposed to outer cool (the style of a product) and inner cool (the personality characteristics assigned to it). In this paper, we focused on inner cool, and we identified 11 inner cool characteristics. These were used to create an initial pool of question items and 2236 participants were asked to assess 16 mobile devices. By performing exploratory and confirmatory factor analyses, we identified three factors that can measure the perceived inner coolness of interactive products: desirability, rebelliousness and usability. These factors and their underlying 16 question items comprise the COOL questionnaire. The whole process of creating the questionnaire is presented in detail in this paper and we conclude by discussing our work against related work on coolness and HCI.

Over the past decade we have seen an increased awareness about domestic energy consumption and a growing focus on eco-feedback displays. In this paper we explore the concept of providing forecasts in such displays as a supplement to information about past usage. Our prototype, eForecast, extends the display of past electricity usage with forecasts about expected usage, electricity price, availability of wind power, and expected demand drops and peaks. Building on previous eco-feedback display research, our approach specifically enables people to use electricity at more opportune times -- when it is cheap, green, or when there is an abundance of capacity. We evaluated eForecast in real world use in three domestic households for 22 weeks, where we explored potentials and limitations of forecasting for shifting electricity consumption. In this way, families were able to act in a more sustainable way -- without necessarily reducing the amount of electricity consumed.

Finding ways to help people quit smoking is a high priority in health behavior change research. Recent HCI studies involving technologies using specific quitting techniques such as social support and SMS messaging to help people quit have reported some success. Early studies using computer generated print material report significant success of tailored versus non-tailored material, however, there is limited understanding on what aspects of digitally delivered quitting assistance should be tailored and how. To address this, we have conducted an empirical investigation with smokers to identify perceived importance of different types of help when quitting and the potential role of technology in providing such help. We found that people are highly individual in their approach to quitting and the kind of help they regard as relevant to their situation. Our contribution is a collection of empirically derived themes for tailoring smoking cessation apps to individual quitting needs.

Recent research has explored the role technology might play in future kitchens, including virtually dining together, recipe sharing, augmented kitchen furniture, reactive cooking utensils and gestural interaction. When people come together in a kitchen to cook it is about more than just production of sustenance -- it is about being together, helping each other, exchanging stories, and contributing to the gradual emergence of a shared meal. In this paper we present a digital ethnography of how people coordinate and cooperate in their kitchens when cooking together for the purpose of inspiring the design of social natural user interactions for technologies in the kitchen. The study is based on 61 YouTube videos of people cooking together analyzed using the frameworks of proxemics and F-formations. Our findings unfold and illustrate relationships between people's spatial organization, their cooking activities and physical kitchen layouts. Based on these we discuss the kitchen as a design space and particularly the opportunities for social natural user interaction design.

We present the design and evaluation of a smartphone app, QuittyLink, designed to help smokers reduce or stop smoking. Smoking cigarettes is a serious health risk and people who wish to quit often struggle to do so. It is well known that the most effective method of assisting smoking cessation is personal face-to-face counseling. However, this approach is only used by very few people wishing to quit for reasons such as inconvenience and personal shyness. In response to this we have created an app that provides personal counseling to users on their smartphone. The counseling content is authored by smoking cessation experts and is based on the user's personal data and recent actual smoking behaviors collected through the smartphone. We deployed the QuittyLink app with people in their everyday lives to study how personal counseling on mobile phones would influence their smoking behaviors. We found that both the personal counseling and the ability to visualize and reflect on their own self-tracked smoking behaviors helped them form strategies to improve their ability to quit.

Regular interactions with nature are vital for the development and wellbeing of children and also to build attachment and value for natural environments that potentially promote proenvironmental behaviour in later life. In this paper, we report on a study designed to identify opportunities for digital technology to support children's connectedness to the natural environment, thereby encouraging positive environmental attitudes in children, as well as healthy physical play. Through participatory engagement with a group of 15 Danish children (aged 812) and their parents, using focus groups and follow up interviews, we explore what motivates children to undertake everyday recreational activities, focusing on activities undertaken in nature, and how these interactions influence meaning associated with their local natural place. The contribution of this paper is a deeper understanding of what motivates children to interact with nature, and a discussion of how technology may enhance this interaction.

Traditional video communication systems offer a very limited experience of eye contact due to the offset between cameras and the screen. In response, we present EyeGaze, which uses multiple Kinect cameras to generate a 3D model of the user, and then renders a virtual camera angle giving the user an experience of eye contact. As a novel approach, we use concepts from KinectFusion, such as a volumetric voxel data representation and GPU accelerated ray tracing for viewpoint rendering. This achieves detail from a noisy source, and allows the real-time video output to be a composite of old and new data. We frame our work in literature on eye contact and previous approaches to supporting it over video. We then describe EyeGaze, and an empirical study comparing it with communication face-to-face or over traditional video. The study shows that while face-to-face is still superior, EyeGaze has added value over traditional video in terms of eye contact, involvement, turn-taking and co-presence.

Recent years have seen an increased research interest in multi-device interactions and digital ecosystems. This research addresses new opportunities and challenges when users are not simply interacting with one system or device at a time, but orchestrate ensembles of them as a larger whole. One of these challenges is to understand what principles of interaction work well for what, and to create such knowledge in a form that can inform design. Our contribution to this research is a framework of interaction principles for digital ecosystems, which can be used to analyze and understand existing systems and design new ones. The 4C framework provides new insights over existing frameworks and theory by focusing specifically on explaining the interactions taking place within digital ecosystems. We demonstrate this value through two examples of the framework in use, firstly for understanding an existing digital ecosystem, and secondly for generating ideas and discussion when designing a new one.

Evaluation is considered one of the major cornerstones of human-computer interaction (HCI). During the last decade, several studies have discussed pros and cons of lab and field evaluations. Based on these discussions, we conduct a review to explore the past decade of mobile HCI research on field and lab evaluation, investigating responses in the literature to the "is it worth the hassle?" paper from 2004. We find that while our knowledge and experience with both lab and field studies have grown considerably, there is still no definite answer to the lab versus field question. In response we suggest that the real question is not if -- but when and how -- to go into the field. In response we suggest moving beyond usability evaluations, and to engage with field studies that are truly in-the-wild, and longitudinal.

Mobile HCI research has started to investigate multi-device interaction as we often have more devices at our immediate disposal. We present an application called JuxtaPinch that allows users to share photos while being collocated using several different devices, i.e. mobile phones and tablets, at the same time. JuxtaPinch use pinching to connect devices and it enables flexible physical positioning of devices and supports partial viewing of photos. Our evaluation showed that JuxtaPinch enabled participants to experience their own familiar photos in new ways known as defamiliarization. It further enabled participants to engage jointly in playful interaction with the photos and with each other. However, we also found that multiple device collocated photo sharing challenges aspects of synchronization and coordination.

We have developed an application called JuxtaPinch that allows users to share photos on multiple devices, i.e. mobile phones and tablets, while being collocated. JuxtaPinch employs simple and intuitive interaction techniques, e.g. pinching to connect devices, and it enables flexible physical positioning of devices and supports partial photo viewing. JuxtaPinch further enables users to use their own devices and access photos stored on own devices. In the Interactivity session, audience members can explore and view photos with friends and colleagues using different devices and experience defamiliarization and playful interaction with the photos -- aspects that we have uncovered during lab and field studies of JuxtaPinch.

When people interact with digital artefacts they perceive their pragmatic and hedonic qualities. In the case of interacting with mobile devices and applications, users seek utility as they try to satisfy certain needs, but at the same time they have certain feelings and emotions when, for example, they feel attached to their personal phone and/or trust its brand. Due to this strong relation between users and mobile devices a significant problem occurs when researchers want to evaluate the user experience of a mobile application in laboratory settings: the selection of an appropriate mobile device. Towards this end, this paper aims to unveil the effect of perceived hedonic quality of a mobile device on the user experience evaluation results of an application. Our results show that the perceived hedonic quality of a mobile device significantly affected the perceived pragmatic quality of the application, but not the hedonic one.

Given the wide adoption of smartphones, an interesting debate is taking place regarding their optimal screen size and specifically whether possible portability issues counterbalance the obvious benefits of a larger screen. Moreover, the lack of scientific evidence about the concrete impact of mobile phones' screen size on usability raises questions both to practitioners and researchers. In this paper, we investigate the impact of a mobile phone's screen size on users' effectiveness, efficiency and perceived usability as measured using System Usability Scale (SUS). An experiment was conducted with 60 participants, which interacted with the same information seeking application on three different devices of the same brand that differed on their screen size. A significant effect of screen size on efficiency was derived, leading to an important finding that users who interact with larger than 4.3in screens are more efficient during information seeking tasks.

Identification of people and their position is essential in the design of proxemic interactions. The smartphone often plays an important role in positioning systems, due to its mobility, computational power and sensory capabilities. Studies however show that perceived proximity to our phone is significantly closer than what is actually the case. This makes the smartphone a weak identifier for applications that need to track persons. With a focus on feasible interaction design, we present a concept and prototype of a platform, which seek to support proxemic interaction beyond weak identifiers. The concept is a lightweight, low-cost, platform, offering a high update-rate that in particular focuses on support for the identity, location and distance dimensions of proxemic interaction. An evaluation of the platform validates its potential use for proxemic interactions but also reveals challenges and limitations that need to be addressed.

In order to take full advantage of the opportunities provided by an increase in consumer device interoperability, we need to explore the design of multi-device systems beyond data sharing between devices. This paper presents an approach to distributed interfaces as technology supporting social interaction in a non-work environment. It consists of a collaborative music system, which in addition to benefit from distributed music storage also distributes playback control onto several mobile devices and provides output through a common situated display. The system has been tested in three different real-life contexts in order to explore the interaction space of non-work multi-device, multi-user environments.

Recent focus on sustainability has made consumers more aware of our joint responsibility for conserving energy resources such as electricity. However, reducing electricity use can be difficult with only a meter and a monthly or annual electricity bill. With the emergence of new power meters units, information on electricity consumption is now available digitally and wirelessly. This enables the design and deployment of a new class of persuasive systems giving consumers insight into their use of energy resources and means for reducing it. In this paper, we explore the design and use of one such system, Power Advisor, promoting electricity conservation through tailored information on a mobile phone or tablet. The use of the system in 10 households was studied over 7 weeks. Findings provide insight into peoples awareness of electricity consumption in their home and how this may be influenced through design.

This paper revisits a research methods survey from 2003 and contrasts it with a survey from 2010. The motivation is to gain insight about how mobile HCI research has evolved over the last decade in terms of approaches and focus. The paper classifies 144 publications from 2009 published in 10 prominent outlets by their research methods and purpose. Comparing this to the survey for 2000-02 show that mobile HCI research has changed methodologically. From being almost exclusively driven by engineering and applied research, current mobile HCI is primarily empirically driven, involves a high number of field studies, and focus on evaluating and understanding, as well as engineering. It has also become increasingly multi-methodological, combining and diversifying methods from different disciplines. At the same time, new opportunities and challenges have emerged.

In recent years there has been an introduction of sophisticated new video conferencing technologies (e.g., HP Halo, Cisco Telepresence) that have led to enhancements in the collaborative user experience over traditional video conferencing technologies. Traditional video conferencing set-ups often distort the shared spatial properties of action and communication due to screen and camera orientation disparities and other asymmetries. These distortions affect access to the common resources used to mutually organize action and communication. By contrast, new systems, such as Halo, are physically configured to reduce these asymmetries and orientation disparities, thereby minimizing these spatial distortions. By creating appropriate shared spatial geometries, the distributed spaces become “blended” where the spatial geometries of the local space continue coherently across the distributed boundary into the remote site, providing the illusion of a single unified space. Drawing on theories of embodied action and workplace design we discuss the importance of this geometric “blending” of space for distributed collaboration and how this is achieved in systems such as Halo. We then extend these arguments to explore the concept of Blended Interaction Spaces : blended spaces in which interactive groupware is incorporated in ways spatially consistent with the physical geometries of the video-mediated set-up. We illustrate this discussion through a system called BISi that introduces interactive horizontal and vertical multipoint surfaces into a blended video-mediated collaboration space. In presenting this system, we highlight some of the particular challenges of creating these systems arising from the spatial consequences of different interaction mechanisms (e.g., direct touch or remote control) and how they affect movement and spatial configuration of people in these spaces.

A lot of research has been done within the area of mobile computing and context-awareness over the last 15 years, and the idea of systems adapting to their context has produced promising results for overcoming some of the challenges of user interaction with mobile devices within various specialized domains. However, today it is still the case that only a limited body of theoretically grounded knowledge exists that can explain the relationship between users, mobile system user interfaces, and their context. Lack of such knowledge limits our ability to elevate learning from the mobile systems we develop and study from a concrete to an abstract level. Consequently, the research field is impeded in its ability to leap forward and is limited to incremental steps from one design to the next. Addressing the problem of this void, this article contributes to the body of knowledge about mobile interaction design by promoting a theoretical approach for describing and understanding the relationship between user interface representations and user context. Specifically, we promote the concept of indexicality derived from semiotics as an analytical concept that can be used to describe and understand a design. We illustrate the value of the indexicality concept through an analysis of empirical data from evaluations of three prototype systems in use. Based on our analytical and empirical work we promote the view that users interpret information in a mobile computer user interface through creation of meaningful indexical signs based on the ensemble of context and system.

As urban environments become increasingly hybridized, mixing the social, built, and digital in interesting ways, designing for computing in the city presents new challenges—how do we understand such hybridization, and then respond to it as designers? Here we synthesize earlier work in human-computer interaction, sociology and architecture in order to deliberately influence the design of digital systems with an understanding of their built and social context of use. We propose, illustrate, and evaluate a multidisciplinary approach combining rapid ethnography, architectural analysis, design sketching, and paper prototyping. Following the approach we are able to provide empirically grounded representations of the socio-physical context of use, in this case people socializing in urban spaces. We then use this understanding to influence the design of a context aware system to be used while out on the town. We believe that the approach is of value more generally, particularly when achieving powerfully situated interactions is the design ambition.

Increased complexity of organizations and emerging technologies poses new and difficult challenges for the evaluation of software systems. Several years of research have proven that usability evaluations are invaluable tools for ensuring the quality of software technologies, but the increased complexity of technology requires new ways of understanding and evaluating the quality of software systems. This article explores limitations, challenges, and opportunities for studying mobile technologies “in use, in situ;” in laboratories (in vitro); and in controlled high-fidelity simulations of the real world. The latter condition is called in sitro. This report comes from 2 different case studies of evaluating the usability of mobile systems within these 3 different conditions. Results show that it is possible to recreate and simulate significant elements of intended future use situations in laboratory settings and thereby increase the level of realism and maintain a high level of control. In fact, the in sitro condition was able to identify most of the same usability problems as found in the other conditions. However, the in situ evaluation proved to provide a level of realism that is difficult to achieve in laboratory environments.

On the basis of a longitudinal field study of domestic communication, we report some essential constituents of the user experience of awareness of others who are distant in space or time, i.e. presence-in-absence.We discuss presence-in-absence in terms of its social (Contact) and informational (Content) facets, and the circumstances of the experience (Context).The field evaluation of a prototype, 'The Cube', designed to support presence-in-absence, threw up issues in the interrelationships between contact, content and context; issues that the designers of similar social artifacts will need to address.

Communication between physically distributed people in industrial and safety-critical domains is often spoken and mediated through walkie-talkies, or closed-circuit intercoms.Because this kind of communication is hampered by noise, radio interference, lack of persistency, etc. vital information is sometimes lost.In response to this challenge, this paper discusses the use of 'canned' text-based messaging as a supplement for improving such communication.Based on data from ethnographic studies of work activities in an industrial domain, and grounded in a theoretical model of communication, we have designed and evaluated a mobile canned communication prototype system facilitating exchange of predefined text messages, a persistent graphical representation of the operation in progress, and a filtered list of completed tasks.Results from two evaluations show that in the domain considered, canned text-based communication has a potential to supplement voice and assist in overcoming some of the inherent problems of spoken communication.Yet using a textual and persistent mode of communication also raises new challenges such as choice of modality, speed, flexibility and handling situations deviating from standard procedures.

Intimacy is a crucial element of domestic life, and many interactive technologies designed for other purposes have been appropriated for use within intimate relationships. However, there is a deficit in current understandings of how technologies are used within intimate relationships, and how to design technologies to support intimate acts. In this paper we report on work that has addressed these deficits. We used cultural probes and contextual interviews and other ethnographically informed techniques to investigate how interactive technologies are used within intimate relationships. From this empirical work we generated a thematic understanding of intimacy and the use of interactional technologies to support intimate acts. We used this understanding to inform the design of intimate technologies. A selection of our design concepts is also presented.

Mobile computer technologies are increasingly being appropriated and used to facilitate people's social life outside the work domain. Addressing this emerging domain of use, we present the design of a context-aware mobile information system prototype facilitating sociality in public places: Just-for-Us. The design of the prototype system was informed by two empirical studies: an architectural analysis of a recently built public space in Melbourne, Australia and a field study of small groups socialising there. We describe these two studies and illustrate how findings informed our prototype design. Finally, we outline an ongoing field study of the use of the Just-for-Us prototype.

When designing a usability evaluation, choices must be made regarding methods and techniques for data collection and analysis. Mobile guides raise new concerns and challenges to established usability evaluation approaches. Not only are they typically closely related to objects and activities in the user's immediate surroundings, they are often used while the user is ambulating. This paper presents results from an extensive, multi-method evaluation of a mobile guide designed to support the use of public transport in Melbourne, Australia. In evaluating the guide, we applied four different techniques; field-evaluation, laboratory evaluation, heuristic walkthrough and rapid reflection. This paper describes these four approaches and their respective outcomes, and discusses their relative strengths and weaknesses for evaluating the usability of mobile guides.

The research presented in this paper aims to inform interface design for mobile guides by understanding and modelling the built environments in which the guide will be used. This is important because research into the use of mobile guides has shown that people have a strong ability to make sense of the physical space in which they are situated and make use of this when using mobile guides. Based on a field study and architectural analysis of the recently built Federation Square in Melbourne, Australia, we present a descriptive framework, MIRANDA, which provides a summarized abstraction of the fundamental architectural and informational features of a built environment. The use of this descriptive framework in HCI design for mobile guides is exemplified through the design of a mobile guide system for Federation Square that was informed by the identified architectural characteristics. On the basis of the field study and example design, we argue that mobile guides interface design can benefit from making use of 'knowledge-in-the-world' by streamlining and indexing information and functionality to physical information cues implicit in the built environment surrounding the user.