Assistive navigational technologies offer considerable promise to people who are blind. However, uptake of these technologies has traditionally been lower in low and middle income countries (LMICs), where levels of investment and maintenance in infrastructure differ from upper middle (UMICs) and high income countries (HICs). In this paper, we describe a qualitative study undertaken with 14 people who identify as legally-blind in an LMIC (India) to understand their experiences and strategies used when navigating within a metropolitan area. We highlight a set of scenarios impacting people who are blind within the context studied. These include crossing busy highways, navigating in the rainy season, collaborating with others to navigate at night, and using older public transportation. Our work brings attention to areas where the latest successful and well-publicized innovations in blind navigation may fall short when used in an Indian metropolitan area. We suggest that designers should be cognizant of the role that infrastructure (particularly its shortcomings) and environmental factors may play when navigating in LMICs such as India, with a view to designing assistive navigational technologies to better match the needs of users within these contexts.

Voice assistants (VAs) – like Amazon Alexa or Siri – offer hands-/eyes-free interactions that are beneficial to a range of users, including individuals who are blind, to fulfill tasks that are otherwise difficult or inaccessible. While these interfaces model conversational interactions to achieve simple tasks, there have been recent calls for VAs that model more transactional interactions for a wider range of complex activities. In this study, we explored the extension of VAs’ capabilities in the context of indoor navigation through mixed-ability focus groups with blind and sighted airport travelers. We found high overlap in the difficulties encountered by blind and sighted travelers, as well as shared interest in a voice-activated travel assistant to improve travel experiences. Leveraging user-elicited recommendations, we present interaction design examples that showcase customization of different and multiple modalities, which collectively demonstrate how VAs can more broadly achieve transactional interactions in complex task scenarios.

Abstract Prior work suggests that older adults are less aware of potential digital privacy risks compared to younger groups. We seek to expand on these findings by using drawmetrics with 20 older adults (60+) to visualize their experiences with digital privacy via drawing sessions. We further compared older adults with 20 adults of working age (18-59) with the goal of identifying both overlapping concerns and key differences that may be missed when viewing each group in isolation. We extended our evaluation with a survey with questions and themes derived from open-coding of the drawn images and confirmed three key differences between the age groups. These include older adults perceiving a greater threat from using online banking and e-commerce compared to working age adults, older adults exhibiting greater levels of concern about global scale threats, and working age adults showing more privacy-related concern regarding social media. Our findings can be used to potentially tailor applications to better accommodate privacy concerns for older adults.

Personal Identification Numbers (PINs) are widely used as an access control mechanism for digital assets (e.g., smartphones), financial assets (e.g., ATM cards), and physical assets (e.g., locks for garage doors or homes). Using semi-structured interviews (n=35), participants reported on PIN usage for different types of assets, including how users choose, share, inherit, and reuse PINs, as well as behaviour following the compromise of a PIN. We find that memorability is the most important criterion when choosing a PIN, more so than security or concerns of reuse. Updating or changing a PIN is very uncommon, even when a PIN is compromised. Participants reported sharing PINs for one type of asset with acquaintances but inadvertently reused them for other assets, thereby subjecting themselves to potential risks. Participants also reported using PINs originally set by previous homeowners for physical devices (e.g., alarm or keypad door entry systems). While aware of the risks of not updating PINs, this did not always deter participants from using inherited PINs, as they were often missing instructions on how to update them. Given the expected increase in PIN-protected assets (e.g., loyalty cards, smart locks, and web apps), we provide suggestions and future research directions to better support users with multiple digital and non-digital assets and more secure human-device interaction when utilizing PINs.

Accessibility researchers have been studying wayfinding technologies for people with disabilities for decades, typically focusing on solutions within disability populations - for example, technologies to support blind navigation. Yet, we know little about wayfinding needs across disabilities. In this paper, we describe a qualitative interview study examining the urban navigational experiences of 27 people who identified as older adults and/or who had cognitive, visual, hearing, and/or mobility disabilities. We found that many navigation route preferences were shared across disabilities (e.g., desire to avoid carpeted areas), while others diverged or were in tension (e.g., the need to avoid noisy areas while staying near main thoroughfares). To support design for multiple disability groups, we identify four dimensions of navigation preferences - technology, route, assistance, experience - and describe how these might usefully inform design of more universally usable wayfinding technologies.

We report on a qualitative inquiry among security-expert and non-expert mobile device users about the adoption of biometric authentication using semi-structured interviews(n=38, 19/19 expert/non-expert). Security experts more readily adopted biometrics than non-experts but also harbored greater distrust towards its use for sensitive transactions,feared biometric signature compromise, and in some cases distrusted newer facial recognition methods. Both groups harbored misconceptions, such as misunderstanding of the functional role of biometrics in authentication, and were about equally likely to have stopped using biometrics due to usability. Implications include the need for tailored training for security-informed advocates, better design for device sharing and co-registration, and consideration for usability needs in work environments. Refinement of these features would remove perceived obstacles to ubiquitous computing among the growing population of mobile technology users sensitized to security risk.

We analyze the claims that video recreations of shoulder surfing attacks offer a suitable alternative and a baseline, as compared to evaluation in a live setting. We recreated a subset of the factors of a prior video-simulation experiment conducted by Aviv et al. (ACSAC 2017), and model the same scenario using live participants (n = 36) instead (i.e., the victim and attacker were both present). The live experiment confirmed that for Android's graphical patterns video simulation is consistent with the live setting for attacker success rates. However, both 4- and 6-digit PINs demonstrate statistically significant differences in attacker performance, with live attackers performing as much 1.9x better than in the video simulation. The security benefits gained from removing feedback lines in Android's graphical patterns are also greatly diminished in the live setting, particularly under multiple attacker observations, but overall, the data suggests that video recreations can provide a suitable baseline measure for attacker success rate. However, we caution that researchers should consider that these baselines may greatly underestimate the threat of an attacker in live settings.

Voice-activated personal assistants (VAPAs)--like Amazon Echo or Apple Siri--offer considerable promise to individuals who are blind due to widespread adoption of these non-visual interaction platforms. However, studies have yet to focus on the ways in which these technologies are used by individuals who are blind, along with whether barriers are encountered during the process of interaction. To address this gap, we interviewed fourteen legally-blind adults with experience of home and/or mobile-based VAPAs. While participants appreciated the access VAPAs provided to inaccessible applications and services, they faced challenges relating to the input, responses from VAPAs, and control of information presented. User behavior varied depending on the situation or context of the interaction. Implications for design are suggested to support inclusivity when interacting with VAPAs. These include accounting for privacy and situational factors in design, examining ways to support concerns over trust, and synchronizing presentation of visual and non-visual cues.

The purpose of this study is to better understand, from an explorative qualitative perspective, the motivations and practices of highly security-conscious users of mobile authentication, and their underlying mental models of those behaviours. Mobile authentication studies have largely overlooked the mindset of these users in the upper bound of security experience, who have considered their behaviour in terms of detailed knowledge of mobile authentication risk. Twenty IT professionals who self-identified as security-conscious mobile device users, many with decades of intensive security-specific experience, were interviewed for this study regarding their opinions and experiences with mobile device authentication and security. These users described usability and situational impairment issues, as well as a deep concern for their identity and data security arising from highly contextual combinations of distrust towards underlying technologies and situational risk. Derived implications for development of security methods adapted to these informed perspectives are discussed and will be the basis for follow-on research comparing these findings with everyday users.

This article describes an exploratory study which examined the use of Brain–Computer Interface (BCI) and gestural technologies generated from a BCI headset as a novel potential alternative to a 4-digit PIN code for authentication. Unlike other input modalities, many of these tokens (i.e., “push,” “lift,” “excitement”), can overcome some of the security vulnerabilities associated with PIN authentication (e.g., observations from third parties). Participants engaged in a controlled study where they performed five, 4-token authentication tasks on a simulated authentication screen. The percentage of completed BCI and gestural input tasks, as well as input time and accuracy, was compared to the 4-digit PIN task. The results showed that while authentication using a BCI headset is currently not as complete, fast, or accurate as that of a 4-digit PIN code, users felt that such a system would represent greater security over PIN-based authentication. In addition, mental commands, which might be perceived as the most secure from the standpoint of inconspicuous detection, were found to offer disappointing results both in terms of completion percentage and completion time.

Given the nature of mobile devices and unlock procedures, unlock authentication is a prime target for credential leaking via shoulder surfing, a form of an observation attack. While the research community has investigated solutions to minimize or prevent the threat of shoulder surfing, our understanding of how the attack performs on current systems is less well studied. In this paper, we describe a large online experiment (n = 1173) that works towards establishing a baseline of shoulder surfing vulnerability for current unlock authentication systems. Using controlled video recordings of a victim entering in a set of 4- and 6-length PINs and Android unlock patterns on different phones from different angles, we asked participants to act as attackers, trying to determine the authentication input based on the observation. We find that 6-digit PINs are the most elusive attacking surface where a single observation leads to just 10.8% successful attacks (26.5% with multiple observations). As a comparison, 6-length Android patterns, with one observation, were found to have an attack rate of 64.2% (79.9% with multiple observations). Removing feedback lines for patterns improves security to 35.3% (52.1% with multiple observations). This evidence, as well as other results related to hand position, phone size, and observation angle, suggests the best and worst case scenarios related to shoulder surfing vulnerability which can both help inform users to improve their security choices, as well as establish baselines for researchers.

This paper describes the design of a graduate level course focusing on developing interfaces for purposes of rehabilitation, catering to students from multiple disciplines. Students work on projects relating to the needs of individuals with disabilities, under the supervision of internal and external mentors. The course has been designed to help students develop both research and mobile interface technical design skills. Course structure and deliverables are described, along with the challenges faced and lessons learned from multiple offerings of the course.

This paper describes an exploratory study examining the feasibility of using Brain-Computer Interface (BCI) and gestural technologies to support individuals who are blind during the authentication process. Four legally-blind participants were asked to don the Emotiv Epoc headset, and authenticate entry using gestural cues, emotional cues and mental commands. Findings highlighted that while BCI and gestural technologies may be slower and less accurate to use compared to four digit PINs, levels of perceived security were higher, as some of these cues were thought to be more difficult for third parties to replicate. A trade-off between perceived security and usability was evident.

This paper describes an exploratory study focusing on the methods of mobile authentication currently utilized by individuals who are blind. Perceptions of security are discussed, along with the trade-offs with usability and accessibility. A tactile aid for a mobile authentication interface was introduced to participants to obtain preliminary feedback on its design. The aid was found to offer promise for supporting orientation, which could be used support novice users, and provide assistance when the mobile device must be used privately in public spaces.

In this paper, we describe an approach to develop alerts for individuals experiencing situationally-induced impairments and disabilities (SIIDs) in inhospitable environments, with a view to support situational awareness and decision making. Our research focuses on the needs of firefighters whose visual and auditory channels may be restricted while performing tasks, resulting in cues sometimes being missed. Through a series of contextual interviews, scenarios have been developed focusing on areas where alerts are required. A participatory-approach has been adopted with the aim of developing perceivable, meaningful and respected alerts, designed to better resist the impacts of SIIDs.

As users become increasingly more reliant on online resources to satisfy their information needs, care is needed to ensure that these resources are credible in nature, especially if a decision is to be taken based upon the information accessed. The credibility of a web site is known to be heavily influenced by its visual appearance. However, for individuals who are blind, challenges are often faced accessing these visual cues when using assistive technologies. In this paper, we describe an observational study to examine the strategies and workarounds developed by individuals who are blind to perform credibility assessments. These are compared with those used by sighted users. Findings from the study have highlighted the relationship between accessibility and credibility. The features used to form assessments non-visually have also been identified. Insights from the study can be used to support the design of highly credible interfaces for blind screen reader users.

Android's graphical authentication mechanism requires users to unlock their devices by "drawing" a pattern that connects a sequence of contact points arranged in a 3x3 grid. Prior studies demonstrated that human-generated 3x3 patterns are weak (CCS'13); large portions can be trivially guessed with sufficient training. An obvious solution would be to increase the grid size to increase the complexity of chosen patterns. In this paper we ask the question: Does increasing the grid size increase the security of human-generated patterns? We conducted two large studies to answer this question, and our analysis shows that for both 3x3 and 4x4 patterns, there is a high incidence of repeated patterns and symmetric pairs (patterns that derive from others based on a sequence of flips and rotations), and many 4x4 patterns are expanded versions of 3x3 patterns. Leveraging this information, we developed an advanced guessing algorithm and used it to quantified the strength of the patterns using the partial guessing entropy. We find that guessing the first 20% (G0.2) of patterns for both 3x3 and 4x4 can be done as efficiently as guessing a random 2-digit PIN. While guessing larger portions of 4x4 patterns (G0.5) requires 2-bits more entropy than guessing the same ratio of 3x3 patterns, it remains on the order of cracking random 3-digit PINs. Of the patterns tested, our guessing algorithm successful cracks 15% of 3x3 patterns within 20 guesses (a typical phone lockout) and 19% of 4x4 patterns within 20 guesses; however, after 50,000 guesses, we correctly guess 95.9% of 3x3 patterns but only 66.7% of 4x4 patterns. While there may be some benefit to expanding the grid size to 4x4, we argue the majority of patterns chosen by users will remain trivially guessable and insecure against broad guessing attacks.

While screen reading technologies offer considerable promise to individuals who are blind by providing an accessible overview of web-based content, difficulties can be faced determining the credibility of sites and their respective contents. This can impact the user's behavior, particularly if sensitive information needs to be entered (e.g. into a web-based form). In this paper, we describe an exploratory study examining the criteria which blind screen reader users utilize to assess credibility. More specifically, we have focused on the common task of web searching and exploring search results. Findings from the study have suggested that mismatches between the title of the search results and their respective snippets, along with the richness and accessibility of the content when search results are selected, can lead to users determining whether sites are indeed credible.

This paper describes a study examining the usability of OnScreenDualScribe (OSDS), a tool to support individuals with physical disabilities with text entry and cursor movement. A portable numeric keypad is used to interact with the OSDS, which can either be held by the user, or can be affixed to a surface for interaction. A study to determine the feasibility of the system was conducted with three individuals with physical disabilities. While it was noted that the time taken was higher to complete a task compared to their existing methods of computer-based input, findings also indicate that the system offers potential for tasks involving a combination of text entry and cursor movement (e.g., completing online forms). Furthermore, as the keypad is smaller in size compared with a traditional keyboard, participants suggested that it offered potential to reduce effort spent in the fatiguing process of traversal.

In this paper, we describe the development of a novel, low-cost, compact sensor/actuator that can be integrated with a commercially-available haptic device, such as the Geomagic Touch, to provide additional capability when grasping virtual objects. The focus of this paper is to investigate the impact of modality on a 'picking and placing' task using the prototype. The results of this study suggest that fewer errors were made when grasping objects presented using force-input/vibrotactile output (FV) combined with force-feedback. The multimodal feedback presented via the prototype is thought to offer considerable potential to supporting skilled and semi-skilled workers to perform remote tasks involving fine motor control.

In this paper, we describe a participatory-based approach to developing tactile feedback for a head-mounted device. Three focus groups iteratively designed and evaluated tactile interaction concepts for user-generated use-case scenarios. Results showed productive design insights from the groups regarding approaches to tactile coding schemes addressing the scenario conditions, as well as method-innovations to participatory design techniques for interaction development in unfamiliar sensory modalities such as touch. The study has culminated in the development of a library of tactile icons relating to spatial concepts, which will be tested as part of future work.

This paper describes two studies that examine the ways in which parameters of touch can be manipulated to support human–mobile interaction, providing designers with greater awareness regarding the range of tactile icons (tactons) for integration with interfaces. The first study examined the efficacy of presenting tactons via low-cost eccentric rotating motor vibration technologies, often used in the design of wearable interfaces. Findings highlight the role of intensity in supporting tactile recognition as well as the impact of duration, interval, and intensity on task time. In our second study, we build on these results by comparing the impact of simulated and real-world auditory distractors on the perception of four parameter tactons. Findings indicate the negative effects of realistic ambient sounds on recognition accuracy, time taken and cognitive workload, but the results also indicate that some tactile designs (e.g. those encoded with stronger intensities) better resist the effects of these auditory distractions. Our research suggests that mobile devices should be evaluated under real-world scenarios to ensure that tactile feedback presented via a mobile device meets the needs of mobile users.

This paper describes a data gathering study, examining the experiences and day-to-day challenges faced by blind web interface developers when designing sites and online applications. Findings have revealed that considerable amounts of time and cognitive effort can be spent checking code in text editing software and examining the content presented via the web browser. Participants highlighted the burden experienced from committing large sections of code to memory, and the restrictions associated with assistive technologies when performing collaborative tasks with sighted developers and clients. Our future work aims to focus on the development of a multimodal web editing and browsing solution, designed to support both blind and sighted parties during the design process.

Although it is well known that interaction with a mobile device can be impacted when the environment is inhospitable or when the user is on the move, situationally-induced impairments and disabilities (SIIDs) are often overlooked in the mobile interface design process. In this paper, we describe one step toward supporting mobile users with SIIDs, through the design of tactile notifications. The tactile channel offers considerable promise to convey notifications to the user, freeing their visual and auditory channels for other tasks. A study was conducted to determine whether participants could develop tactile cues to convey the key characteristics of alerts to mobile users (e.g. urgency, relationship with the sender). The results highlight the benefits of tactile prototyping tools to encourage generation of design ideas, and the use of scenarios to situate these design ideas within the intended context of use.

In this paper, we describe an exploratory study to determine the feasibility of using a low-cost gestural headset to support communication. Findings have shown tasks involving facial gestures, such as blinks and smiles, can be performed and detected by an Augmented and Alternative Communication (AAC) system within a shorter period of time compared to brow movements. As tasks increase in complexity, rates of accuracy and time taken remain relatively constant for blinking gestures, highlighting their potential in AAC interfaces. We aim to refine such a system to better address the needs of individuals with disabilities, by limiting input errors from involuntary movements and examining ways to reduce interface navigation time. Insights gained from the study offer promise to interface designers seeking to widen access to their interfaces using gestural input.

Interpersonal communication benefits greatly from the emotional information encoded by facial expression, body language, and tone of voice. However, these cues are often lost when sending text-based instant messages. This article describes a novel approach utilizing gestural and brain–computer interface (BCI) input to replace the missing emotional cues, with the aim of augmenting the instant messaging process. A set of exploratory studies were conducted using a commercially available BCI headset. An initial study validated the emotional data automatically captured by the device. Subsequently, an instant messaging application was developed, which detected emotions and facial gestures that are presented to the user's chat partner via progress bars and an avatar. Findings from an evaluation revealed that the novel approach facilitates communication containing a greater percentage of affective terms compared with traditional, text-based instant messaging environments. Strong levels of confidence were expressed when using the system to both convey and infer affective states, contributing to a rich subjective user experience.

This paper describes a Science-Technology-Engineering-Mathematics (STEM) outreach workshop conducted with post-secondary students diagnosed with learning differences, including Learning Disabilities (LD), Attention Deficit / Hyperactivity Disorders (AD/HD), and/or Autism Spectrum Disorders (ASD). In this workshop, students were actively involved in participatory design exercises such as data gathering, identifying accessible design requirements, and evaluating mobile applications and games targeted for diverse users. This hands-on experience broadened students' understanding of STEM areas, provided them with an opportunity to see themselves as computer scientists, and demonstrated how they might succeed in computing careers, especially in human-centered computing and interface design. Lessons learned from the workshop also offer useful insight on conducting participatory design with this unique population.

In this paper, we describe a first step towards the development of a solution to support the movement and repositioning of an individual's limbs. Limb repositioning is particularly valuable for individuals with physical disabilities who are either bed or chair-bound, to help reduce the occurrence of contractures and pressure ulcers. A data gathering study has been performed examining attitudes towards using BCI and gestural devices to control a robotic aid to assist with the repositioning process. Findings from a preliminary study evaluating a controller interface prototype suggest that while BCI and gestural technologies may play a valuable role in limiting fatigue from interacting with a mouse or other input device, challenges are faced accurately identifying specific facial expressions (e.g. blinks). Future work would aim to refine algorithms to detect gestures, with a view to augmenting the experience when using a BCI and gestural device to control a robotic aid.

Older adults are recommended to remain physically active to reduce the risk of chronic diseases and to maintain psychological well-being. At the same time, research also suggests that levels of fitness can be raised among this group. This paper describes the development and evaluation of a mobile technology, which enables older adults to monitor and modify their walking habits, with the long-term aim of sustaining appropriate levels of physical activity. An empirical study was conducted with twenty older adults to determine the feasibility of the proposed solution, with results indicating that tactile signals could be perceived while in motion and could support participants in walking at a range of paces. However, the effects were difficult to discern due to limitations of the hardware. In response, a novel low-cost prototype was developed to amplify vibrations, and effectiveness of redundant auditory information was investigated with the goal of enhancing the perception of the cues. A second study was conducted to determine the impact of multimodal feedback on walking behavior. Findings revealed that participants were able to maintain a desired level of pace more consistently when redundant auditory information was presented alongside the tactile feedback. When the visual channel is not available, these results suggest that tactile cues presented via a mobile device should be augmented with auditory feedback. Our research also suggests that mobile devices could be made more effective for alternative applications if they are designed to allow for stronger tactile feedback.

Haptic technologies are often used to improve access to the structural content of graphical user interfaces, thereby augmenting the interaction process for blind users. While haptic design guidelines offer valuable assistance when developing non-visual interfaces, the recommendations presented are often tailored to the feedback produced via one particular haptic input/output device. A blind user is therefore restricted to interacting with a device which may be unfamiliar to him/her, rather than selecting from the range of commercially available products. This paper reviews devices available on the first and second-hand markets, and describes an exploratory study undertaken with 12 blindfolded sighted participants to determine the effectiveness of three devices for non-visual web interaction. The force-feedback devices chosen for the study, ranged in the number of translations and rotations that the user was able to perform when interacting with them. Results have indicated that the Novint Falcon could be used to target items faster in the first task presented, compared with the other devices. However, participants agreed that the force-feedback mouse was most comfortable to use when interacting with the interface. Findings have highlighted the benefits which low cost haptic input/output devices can offer to the non-visual browsing process, and any changes which may need to be made to accommodate their deficiencies. The study has also highlighted the need for web designers to integrate appropriate haptic feedback on their web sites to cater for the strengths and weaknesses of various devices, in order to provide universally accessible sites and online applications.

This paper describes the design of an accessible authentication mechanism. The Tactile Authentication System has been adapted to enable individuals who are blind to access electronic data using their sense of touch. To enter the system, users must identify a set of pre-selected pin-based icons from a wider range presented via a tactile mouse. As information is presented underneath the user's fingertips, 'tactile passwords' are shielded from observers, thereby enhancing security from third-party attacks. Results from a pilot study showed that five participants were able to authenticate entry to the non-visual interface over the course of a two week period. However, findings have revealed that the time needed to perform this process should be reduced to improve the quality of the user experience.

This paper describes a study designed to identify salient tactile cues which can be integrated with a cellular telephone interface, to provide non-visual feedback to users when accessing mobile applications. A set of tactile icons (tactons) have been developed by manipulating the pulse duration and interval of vibrotactile signals. Participants were presented with pairs of tactons, and asked to differentiate between each respective pair and rank their salience. Results suggested that the combination of two static tactons is the most effective way to convey tactile information, when compared with dynamic or mixed tactile cues. Further studies will be conducted to refine feedback in order to communicate the presence of graphical objects on a mobile device interface, or to present events and alerts more effectively. The long term goal is to improve access to an interface by using the tactile channel, thereby freeing the visual and auditory channels to perform other tasks.

Haptic technologies are thought to have the potential to help blind individuals overcome the challenges experienced when accessing the Web. This paper proposes a structured participatory-based approach for developing targeted haptic sensations for purposes of web page exploration, and reports preliminary results showing how HTML elements can be represented through the use of force-feedback. Findings are then compared with mappings from previous studies, demonstrating the need for providing tailored haptic sensations for blind Internet users. This research aims to culminate in a framework, encompassing a vocabulary of haptic sensations with accompanying recommendations for designers to reference when developing inclusive web solutions.