Everyday talk is often treated as casual chatter, yet it plays a crucial role in how people acquire and share knowledge. Typically, cybersecurity practices are informed by formal training, but they often overlook the impact of social exchanges. This paper investigates how informal conversations can act as a socio-technical mechanism for shaping cybersecurity awareness and practices. We conducted an online survey (N=215) where participants described recent discussions about cybersecurity, including who was involved, where they took place, and what triggered them. Quantitative and thematic analysis revealed common contexts, social settings, and topics. Most conversations occurred spontaneously in private environments, with personal experiences being the most frequent trigger. We contribute empirical insights on informal security conversations to inform the design of human-centered technologies that surface and mediate security-related discussions in everyday contexts, to ensure implicit and continuous security awareness.

We propose a novel method for seamlessly identifying users by combining thermal and visible feet features. While it is known that users’ feet have unique characteristics, these have so far been underutilized for biometric identification, as observing those features often requires the removal of shoes and socks. As thermal cameras are becoming ubiquitous, we foresee a new form of identification, using feet features and heat traces to reconstruct the footprint even while wearing shoes or socks. We collected a dataset of users’ feet (N = 21), wearing three types of footwear (personal shoes, standard shoes, and socks) on three floor types (carpet, laminate, and linoleum). By combining visual and thermal features, an AUC between 91.1% and 98.9%, depending on floor type and shoe type can be achieved, with personal shoes on linoleum floor performing best. Our findings demonstrate the potential of thermal imaging for continuous and unobtrusive user identification.

Existing virtual reality (VR) authentication schemes are either slow or prone to observation attacks. We propose CueVR, a cue-based authentication scheme that is resilient against observation attacks by design since vital cues are randomly generated and only visible to the user experiencing the VR environment. We investigate three different input modalities through an in-depth usability study (N=20) and show that while authentication using CueVR is slower than the less secure baseline, it is faster than existing observation resilient cue-based schemes and VR schemes (4.151 s – 7.025 s to enter a 4-digit PIN). Our results also indicate that using the controllers’ trackpad significantly outperforms input using mid-air gestures. We conclude by discussing how visual cues can enhance the security of VR authentication while maintaining high usability. Furthermore, we show how existing real-world authentication schemes combined with VR’s unique characteristics can advance future VR authentication procedures.

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

We present PriView, a concept that allows privacy-invasive devices in the users’ vicinity to be visualised. PriView is motivated by an ever-increasing number of sensors in our environments tracking potentially sensitive data (e.g., audio and video). At the same time, users are oftentimes unaware of this, which violates their privacy. Knowledge about potential recording would enable users to avoid accessing such areas or not to disclose certain information. We built two prototypes: a) a mobile application capable of detecting smart devices in the environment using a thermal camera, and b) VR mockups of six scenarios where PriView might be useful (e.g., a rental apartment). In both, we included several types of visualisation. Results of our lab study (N=24) indicate that users prefer simple, permanent indicators while wishing for detailed visualisations on demand. Our exploration is meant to support future designs of privacy visualisations for varying smart environments.

Fitness trackers have the potential for fostering sustained change and increasing well-being. However, the research community is yet to understand what design features and values need to be embodied in a fitness tracker for long-term engagement. While past work mainly focused on WEIRD (Western, Educated, Industrialised, Rich, Democratic) fitness trackers usersin North America and Western Europe, this paper investigates another perspective on fitness tracking. We conducted interviews with N = 37 fitness tracker users in the US, Europe and Egypt to identify the similarities and differences in attitudes and practices in fitness tracking. We found that fitness tracking involved a deeper social context in Egyptian communities and our findings suggest that Arabic users focused on physiological measurement, while non-Arab Western users appear to bewere more interested in goal achievement. We contribute design dimensions that can help build more inclusive tracker experiences. Our work highlights how future fitness trackers should support a customisable spectrum of design values to offer engaging experiences to a diverse and global audience.

Tablets are attractive for design work anywhere, but 3D manipulations are notoriously difficult. We explore how engaging the stylus and multi-touch in concert can render such tasks easier. We introduce Bi-3D, an interaction concept where touch gestures are combined with 2D pen commands for 3D manipulation. For example, for a fast and intuitive 3D drag & drop technique: the pen drags the object on-screen, and parallel pinch-to-zoom moves it in the third dimension. In this paper, we describe the Bi-3D design space, crossing two-handed input and the degrees-of-freedom (DOF) of 3D manipulation and navigation tasks. We demonstrate sketching and manipulation tools in a prototype 3D design application, where users can fluidly combine 3D operations through alternating and parallel use of the modalities. We evaluate the core technique, bi-manual 3DOF input, against widget and mid-air baselines in an object movement task. We find that Bi-3D is a fast and practical way for multi-dimensional manipulation of graphical objects, promising to facilitate 3D design on stylus and tablet devices.

We investigate opportunities and challenges of running virtual reality (VR) studies remotely. Today, many consumers own head-mounted displays (HMDs), allowing them to participate in scientific studies from their homes using their own equipment. Researchers can benefit from this approach by being able to recruit study populations normally out of their reach, and to conduct research at times when it is difficult to get people into the lab (cf. the COVID pandemic). In an initial online survey ( N = 227), we assessed HMD owners’ demographics, their VR setups and their attitudes toward remote participation. We then identified different approaches to running remote studies and conducted two case studies for an in-depth understanding. We synthesize our findings into a framework for remote VR studies, discuss strengths and weaknesses of the different approaches, and derive best practices. Our work is valuable for Human-Computer Interaction (HCI) researchers conducting VR studies outside labs.

Recent work showed that using image processing techniques on thermal images taken by high-end equipment reveals passwords entered on touchscreens and keyboards. In this paper, we investigate the susceptibility of common touch inputs to thermal attacks when non-expert attackers visually inspect thermal images. Using an off-the-shelf thermal camera, we collected thermal images of a smartphone's touchscreen and a laptop's touchpad after 25 participants had entered passwords using touch gestures and touch taps. We show that visual inspection of thermal images by 18 participants reveals the majority of passwords. Touch gestures are more vulnerable to thermal attacks (60.65% successful attacks) than touch taps (23.61%), and attacks against touchscreens are more accurate than on touchpads (87.04% vs 56.02%). We discuss how the affordability of thermal attacks and the nature of touch interactions make the threat ubiquitous, and the implications this has on security.

With the rise of the Internet of Things, home appliances become connected and they can proactively provide status information to users. Facing a steadily increasing number of notification sources, it is unclear how information from smart home devices should be provided without overloading the users’ attention. In this paper, we investigate the design of non-urgent smart home notifications using a smart plant system. Based on feedback from focus groups, we designed four notification types and compared them in an eight-week in-situ study. We show that notifications displayed on smart home devices are preferred to those received on smartphones. Event-based notifications are unobtrusive, actionable and are preferred to persistent notifications. We derive guidelines that address the need of being in control, opportune locations for notification delivery at opportune moments, notification blindness, the importance of discretizing continuous information, and combining related notifications.

While Augmented Reality (AR) technologies are becoming increasingly available, our understanding of AR is primarily limited to controlled experiments which address use at work or for entertainment. Little is known about how it could enhance everyday interaction from a user's perspective. Personal use of AR at home may improve how users' interface with information on a daily basis. Through an online survey, we investigated attitudes towards domestic AR. We further explored the opportunities for AR at home in a technology probe. We first introduced the users to AR by offering an AR experience presented through mixed reality smart glasses. We then used a tailor-made tablet application to elicit photos illustrating how users imagine future AR experiences. Finally, we conducted semi-structured interviews based on elicited photos. Our results show that users are eager to benefit from on-demand information, assistance, enhanced sensory perception, and play offered by AR across many locations at home. We contribute insights for future AR systems designed for domestic environments.

Recent work demonstrated the opportunities of thermal imaging in the development of novel interactive systems. However, the exploration is limited to controlled lab setups. Hence, little we know about how thermal imaging could be useful for a broader range of daily applications by novice users. To investigate the potential of domestication of thermal imaging, we conducted an exploration with a technology-cultural probe. Ten households (26 individuals) used a mobile thermal camera in their daily life. We collected thermal photos taken by the participants and conducted interviews after using the camera. We found that the users were excited about using thermal cameras in their everyday lives and found many practical uses for them. Our study provides insights into how novice users wish to use thermal imaging technology to augment their vision in daily setups, as well as identifying and classifying common thermal imaging use cases. Our work contributes implications for designing thermal imaging devices targeted towards novice users.

Human vision is limited to a small band of the electromagnetic spectrum. It has been shown that extending visual perception can be beneficial, but it is unclear if this is useful for a broader range of applications. In this paper, we explore user reactions to extended visual perception. We describe the design and implementation of TriSight, a head-mounted display that allows the user to perceive the environment in the visual spectrum, the thermal spectrum, and through depth maps. In a study, we asked participants to perform everyday tasks in a created home, kitchen, office and basement with TriSight. Through analyzing videos, interviews, questionnaires and logs we chart the users' feedback towards the augmented visual perception. Our findings, imply the positive impact of extended vision, as well as the potential of thermal vision as alternative perception mode in performing daily tasks. Finally, we discuss the implications for designing devices that extend human's visual perception beyond the visual spectrum.

Now that most daily endeavors have migrated to computers and the Internet, having systems that adapt to users is a rising trend. By detecting and adapting to the user's traits and character instead of only the current states, there is great potential for novel user experiences. Character Computing which was introduced in [3] is now extended to the field of experimental psychology and psychological theorizing. Our approach integrates psychological and computational aspects of advanced sensing and processing technologies to detect the building blocks of a user's character traits and states which will allow computer systems to adapt to the user's behavior and his/her feelings more reliably and mimic them according to situational demands. Accordingly, in this workshop the different aspects of Character Computing are to be discussed from an interdisciplinary perspective taking computational and psychological accounts into consideration in order to strengthen already investigated and potential applications as well as the theoretical foundation and challenges of Character Computing.

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

Most of the current adaptive systems support single task activities. The rise in the number of daily interactive devices and sources of information made multitasking an integral activity in our daily life. Affect-aware systems show exciting potential to support the user, however, they focus on the induced effect of an additional task in terms of cognitive load and stress, rather than the influence of the number of tasks i.e. multitasking. This paper presents indicators of the number of tasks being performed by the user using a set of bio-sensors. A preliminary user study was conducted with two follow-up explorations. Our findings imply that we can distinguish between the number of tasks performed based on high-end as well as cheap Heart Rate sensors. Additionally, tasks number correlates with other signals, namely wrist and forehead temperature. We provide empirical evidence showing how to differentiate between single- and dual-tasking activities.

Adaptive educational games have shown potential in enhancing the learning experience in educational setups. Most of the conducted research used the content and level of difficulty as the adaptive aspect. However, in this work we aim to evaluate the effect of changing the game interface including; background music and color as well as dynamics represented by the timer and scoring technique. We built adaptive educational games using subjective measures, where the adaptive features are manipulated based on reported emotions by the participants. We conducted a between subject study with 30 participants using adaptive and non-adaptive version of the game to assess the effectiveness of the proposed adaptive aspects on the learning experience, namely, learning gain and the engagement level. Our findings showed a significant increase in the learning gain and the engagement level of the participants who used the adaptive version of the system over the other. Finally, we discuss the implication of our findings and potential added value of our findings.

PINs and patterns remain among the most widely used knowledge-based authentication schemes. As thermal cameras become ubiquitous and affordable, we foresee a new form of threat to user privacy on mobile devices. Thermal cameras allow performing thermal attacks, where heat traces, resulting from authentication, can be used to reconstruct passwords. In this work we investigate in details the viability of exploiting thermal imaging to infer PINs and patterns on mobile devices. We present a study (N=18) where we evaluated how properties of PINs and patterns influence their thermal attacks resistance. We found that thermal attacks are indeed viable on mobile devices; overlapping patterns significantly decrease successful thermal attack rate from 100% to 16.67%, while PINs remain vulnerable (>72% success rate) even with duplicate digits. We conclude by recommendations for users and designers of authentication schemes on how to resist thermal attacks.

Most of the typical digital systems are not fully aware of the users' affect states. Adapting to the users' state showed great potential for enhancing user experiences. However, most approaches for sensing affective states, specifically arousal and valence, involve expensive and obtrusive technologies, such as physiological sensors attached to users' bodies. This paper present an indicator of the users' affect based on eye tracking. We use a commercial eye tracker to monitor the user's pupil size to estimate their arousal and valence in response to videos of different content. To assess the effect of different content (namely pleasant and unpleasant) influencing the arousal and valence on the pupil diameter, we conducted a user study with 25 participants. The study showed that different content of videos affect the pupil diameter, thereby giving an indicator about the user's state. We provide empirical evidence showing how to unobtrusively detect changes in users' state. Our initial investigation gives rise to eye-based user's tracking, which introduces the potential of new applications in the field of affect-aware computing.

Due to the rise of lifelog cameras, we have personal video data that is too large to be watched. Video indexing has the potential to provide meta-information for faster video search. This work aims to support lifelog video indexing through automated face priority rating. In a user study, we identified parameters that allow for rating the importance of persons in a video. We implemented these findings to automatically predict the person's importance in video. We show that our algorithm predicts similar person priority ratings like the participants had given. Hence, we contribute to video-based lifelogging through indicating, implementing, and testing face indexing rules that predict how important a person in a video is perceived. Our findings can help to build video players that support users navigating through their large video data and reviewing sequences that recall important moments of life.

Recent work demonstrated the exciting opportunities that thermal imaging offers for the development of interactive systems. It was shown that a thermal camera can sense when a user touches a surface, performs gestures in the camera's direct field of view and, in addition, performs gestures outside the camera's direct field of view through thermal reflection. In this paper, we investigate the material properties that should be considered for detecting interaction using thermal imaging considering both in- and outdoor settings. We conducted a study to analyze the recognition performance for different gestures and different surfaces. Using the results, we derive guidelines on material properties of surfaces for detecting on-surface as well as mid-air interaction using a thermal camera. We discuss the constrains that should be taken into account using thermal imaging as the sensing technology. Finally, we present a material space based on our findings. The space depicts surfaces and the required properties that enable the different interaction techniques.

With an increasing number of new camera devices entering the market, lifelogging has turned into a viable everyday practice. The promise of comprehensively capturing our life's happenings has caused adoption rates to grow, but approaches to do so greatly differ. In this paper we evaluate existing visual lifelogging capture approaches through a user study with two main capture dimensions: (1) comparing the body position where a lifelogging camera is worn: head versus chest (2) comparing the media captures: video versus stills. We equipped 30 participants with cameras on their heads and chests. That data was evaluated by subjective user ratings as well as by objective image processing analysis. Our findings indicate that (1) chest-worn devices are more stable and contain less motion blur through which feature detection by image processing algorithms works better than from head-worn cameras; 2) head-worn video cameras, however, seem to be the better choice for lifelogging as they capture more important autobiographical cues than chest-worn devices, e.g., faces that have been shown to be most relevant for recall.

Thermal cameras have recently drawn the attention of HCI researchers as a new sensory system enabling novel interactive systems. They are robust to illumination changes and make it easy to separate human bodies from the image background. Far-infrared radiation, however, has another characteristic that distinguishes thermal cameras from their RGB or depth counterparts, namely thermal reflection. Common surfaces reflect thermal radiation differently than visual light and can be perfect thermal mirrors. In this paper, we show that through thermal reflection, thermal cameras can sense the space beyond their direct field-of-view. A thermal camera can sense areas besides and even behind its field-of-view through thermal reflection. We investigate how thermal reflection can increase the interaction space of projected surfaces using camera-projection systems. We moreover discuss the reflection characteristics of common surfaces in our vicinity in both the visual and thermal radiation bands. Using a proof-of-concept prototype, we demonstrate the increased interaction space for hand-held camera-projection system. Furthermore, we depict a number of promising application examples that can benefit from the thermal reflection characteristics of surfaces.