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Accessibility barriers in mobile applications (apps) can make it challenging for people who have impairments or use assistive technology to use those apps. Ross et al.’s epidemiology-inspired framework emphasizes that a wide variety of factors may influence an app's accessibility and presents large-scale analysis as a powerful tool for understanding the prevalence of accessibility barriers (i.e., inaccessibility diseases ). Drawing on this framework, we performed a large-scale analysis of free Android apps, exploring the frequency of accessibility barriers and factors that may have contributed to barrier prevalence. We tested a population of 9,999 apps for seven accessibility barriers: few TalkBack-focusable elements, missing labels, duplicate labels, uninformative labels, editable TextViews with contentDescription , fully overlapping clickable elements, and undersized elements. We began by measuring the prevalence of each accessibility barrier across all relevant element classes and apps. Missing labels and undersized elements were the most prevalent barriers. As a measure of the spread of barriers across apps, we assessed the five most reused classes of elements for missing labels and undersized elements. The Image Button class was among the most barrier-prone of the high reuse element classes; 53% of Image Button elements were missing labels and 40% were undersized. We also investigated factors that may have contributed to the high barrier prevalence in certain classes of elements, selecting examples based on prior knowledge, our analyses, and metrics of reuse and barrier-proneness. These case studies explore: (1) how the few TalkBack-focusable elements accessibility barrier relates to app category (e.g., Education, Entertainment) and the tools used to implement an app, (2) the prevalence of label-based barriers in image-based buttons, (3) design patterns that affect the labeling and size of Radio Buttons and Checkboxes, and (4) accessibility implications of the sizing of third-party plug-in elements. Our work characterizes the current state of Android accessibility, suggests improvements to the app ecosystem, and demonstrates analysis techniques that can be applied in further app accessibility assessments.

In an era of rapidly evolving technology and increasing interconnection, full participation in society depends on the successful use of technology. Thus, to ensure equity and participation for people with disabilities, technology must be accessible - we must create and adapt interactive systems to improve access to technology and to the world at large. The University of Washington Center for Research and Education on Accessible Technology and Experiences (CREATE) is dedicated to propelling accessible technology research and education from incremental improvements to paradigm-shifting breakthroughs that enable greater inclusion and participation for people of all abilities.

By focusing on users' abilities rather than disabilities, designers can create interactive systems better matched to those abilities.

Despite years of addressing disability in technology design and advocating user-centered design practices, popular mainstream technologies remain largely inaccessible for people with disabilities. We conducted a design course study investigating how student designers regard disability and explored how designing for multiple disabled and nondisabled users encouraged students to think about accessibility in the design process. Across two university course offerings one year apart, we examined how students focused on a design project while learning user-centered design concepts and techniques, working with people with and without disabilities throughout the project. In addition, we compared how students incorporated disability-focused design approaches within a classroom setting. We found that designing for multiple stakeholders with and without disabilities expanded student understanding of accessible design by demonstrating that people with the same disability could have diverse needs and by aligning such needs with those of nondisabled users. We also found that using approaches targeted toward designing for people with disabilities complemented interactions with users, particularly with regard to managing varying abilities across users, or incorporating social aspects. Our findings contribute to an understanding about how we might incur change in design practice by working with multiple stakeholders with and without disabilities whenever possible. We refined Design for Social Accessibility by incorporating these findings into three tenets emphasizing: (1) design for disability ought to incorporate users with and without disabilities, (2) design should address functional and social factors simultaneously, and (3) design should include tools to spur consideration of social factors in accessible design.

With the recent influx of smartphones, tablets, and wearables such as watches and glasses, personal interactive device use is increasingly visible and commonplace in public and social spaces. Assistive Technologies (ATs) used by people with disabilities are observable to others and, as a result, can affect how AT users are perceived. This raises the possibility that what we call “social accessibility” may be as important as “functional accessibility” when considering ATs. But, to date, ATs have almost exclusively been regarded as functional aids. For example, ATs are defined by the Technical Assistance to the States Act as technologies that are “used to increase, maintain or improve functional capabilities of individuals with disabilities.” To investigate perceptions and self-perceptions of AT users, we conducted a diary study of two groups of participants: people with disabilities and people without disabilities. Our goal was to explore the types of interactions and perceptions that arise around AT use in social and public spaces. During our 4-week study, participants with sensory disabilities wrote about feeling either self-conscious or self-confident when using an assistive device in a social or public situation. Meanwhile, participants without disabilities were prompted to record their reactions and feelings whenever they saw ATs used in social or public situations. We found that AT form and function does influence social interactions by impacting self-efficacy and self-confidence. When the design of form or function is poor, or when inequality between technological accessibility exists, social inclusion is negatively affected, as are perceptions of ability. We contribute a definition for the “social accessibility” of ATs and subsequently offer Design for Social Accessibility (DSA) as a holistic design stance focused on balancing an AT user's sociotechnical identity with functional requirements.

Mobile sign language video conversations can become unintelligible if high video transmission rates cause network congestion and delayed video. In an effort to understand the perceived lower limits of intelligible sign language video intended for mobile communication, we evaluated sign language video transmitted at four low frame rates (1, 5, 10, and 15 frames per second [fps]) and four low fixed bit rates (15, 30, 60, and 120 kilobits per second [kbps]) at a constant spatial resolution of 320 × 240 pixels. We discovered an “intelligibility ceiling effect,” in which increasing the frame rate above 10fps did not improve perceived intelligibility, and increasing the bit rate above 60kbps produced diminishing returns. Given the study parameters, our findings suggest that relaxing the recommended frame rate and bit rate to 10fps at 60kbps will provide intelligible video conversations while reducing total bandwidth consumption to 25% of the ITU-T standard (at least 25fps and 100kbps). As part of this work, we developed the Human Signal Intelligibility Model , a new conceptual model useful for informing evaluations of video intelligibility and our methodology for creating linguistically accessible web surveys for deaf people. We also conducted a battery-savings experiment quantifying battery drain when sign language video is transmitted at the lower frame rates and bit rates. Results confirmed that increasing the transmission rates monotonically decreased the battery life.

Gesture-based system are becoming ubiquitous. Trablets, phones, large displays, and even laptop computers are now commonly equipped with multitouch-recognizing screens. Third-party accessories like the Wii Nunchuck and the Xbox Kinect can also detect.

Current approaches to accessible computing share a common goal of making technology accessible to users with disabilities. Perhaps because of this goal, they may also share a tendency to centralize disability rather than ability. We present a refinement to these approaches called ability-based design that consists of focusing on ability throughout the design process in an effort to create systems that leverage the full range of human potential. Just as user-centered design shifted the focus of interactive system design from systems to users, ability-based design attempts to shift the focus of accessible design from disability to ability. Although prior approaches to accessible computing may consider users’ abilities to some extent, ability-based design makes ability its central focus. We offer seven ability-based design principles and describe the projects that inspired their formulation. We also present a research agenda for ability-based design.

Prior research shows that people with motor impairments face considerable challenges when using conventional mice and trackballs. One challenge is positioning the mouse cursor within confined target areas; another is executing a precise click without slipping. These problems can make mouse pointing in graphical user interfaces very difficult for some people. This article explores goal crossing as an alternative strategy for more accessible target acquisition. In goal crossing, targets are boundaries that are simply crossed by the mouse cursor. Thus, goal crossing avoids the two aforementioned problems. To date, however, researchers have not examined the feasibility of goal crossing for people with motor difficulties. We therefore present a study comparing area pointing and goal crossing. Our performance results indicate that although Fitts' throughput for able-bodied users is higher for area pointing than for goal crossing (4.72 vs. 3.61 bits/s), the opposite is true for users with motor impairments (2.34 vs. 2.88 bits/s). However, error rates are higher for goal crossing than for area pointing under a strict definition of crossing errors (6.23% vs. 1.94%). We also present path analyses and an examination of submovement velocity, acceleration, and jerk (the change in acceleration over time). These results show marked differences between crossing and pointing and almost categorically favor crossing. An important finding is that crossing reduces jerk for both participant groups, indicating more fluid, stable motion. To help realize the potential of goal crossing for computer access, we offer design concepts for crossing widgets that address the occlusion problem, which occurs when one crossing goal obscures another in persistent mouse-cursor interfaces. This work provides the motivation and initial steps for further exploration of goal crossing on the desktop, and may help researchers and designers to radically reshape user interfaces to provide accessible goal crossing, thereby lowering barriers to access.

Recent improvements in text entry error rate measurement have enabled the running of text entry experiments in which subjects are free to correct errors (or not) as they transcribe a presented string. In these “unconstrained” experiments, it is no longer necessary to force subjects to unnaturally maintain synchronicity with presented text for the sake of performing overall error rate calculations. However, the calculation of character-level error rates, which can be trivial in artificially constrained evaluations, is far more complicated in unconstrained text entry evaluations because it is difficult to infer a subject's intention at every character. For this reason, prior character-level error analyses for unconstrained experiments have only compared presented and transcribed strings, not input streams. But input streams are rich sources of character-level error information, since they contain all of the text entered (and erased) by a subject. The current work presents an algorithm for the automated analysis of character-level errors in input streams for unconstrained text entry evaluations. It also presents new character-level metrics that can aid method designers in refining text entry methods. To exercise these metrics, we perform two analyses on data from an actual text entry experiment. One analysis, available from the prior work, uses only presented and transcribed strings. The other analysis uses input streams, as described in the current work. The results confirm that input stream error analysis yields richer information for the same empirical data. To facilitate the use of these new analyses, we offer pseudocode and downloadable software for performing unconstrained text entry experiments and analyzing data.

This paper describes the author's dissertation research on designing, implementing, and evaluating the Edge Write text entry method. The goal of this research is to develop a method that is highly "robust," remaining accessible and accurate across a variety of devices, abilities, circumstances, and constraints. Edge Write is particularly aimed at users with motor impairments and able-bodied users "on the go." To date, this research has resulted in versions of Edge Write for PDAs, touchpads, displacement joysticks, isometric joysticks, trackballs, 4-keys, and more, all of which use the same Edge Write alphabet and concepts. The stylus version, for instance, has been shown to be significantly more accurate than Graffiti for both able-bodied and motor-impaired users. Similarly, the trackball version has been shown to be better than on-screen keyboards for some people who use trackballs due to motor impairments. This paper discusses these and other achievements, and points towards future work on a mobile phone version for situationally-impaired users. From its inception, Edge Write has been developed with the help of participants, both able-bodied and motor-impaired.

Editor's Note: New fields, such as computer science, cognitive science, neuroscience, human-computer interaction, and now information, have multidisciplinary origins. To overcome communication difficulties as they worked to define the field and set priorities, pioneers developed a pidgin language. Soon came a generation of scholars, who staked their careers on the new field, creolizing the language and shaping a coherent framework relatively free of the legacy disciplines. In this article three research faculty members from the Information School of the University of Washington, discuss the tensions and opportunities in this 21st-century discipline that could become the most influential of all. ---Jonathan Grudin