Unauthorized physical access to personal devices by people known to the owner of the device is a common concern, and a common occurrence. But how do people experience incidents of unauthorized access? Using an online survey, we collected 102 accounts of unauthorized access. Participants wrote stories about past situations in which either they accessed the smartphone of someone they know, or someone they know accessed theirs. We describe the context leading up to these incidents, the course of events, and the consequences. We then identify two orthogonal themes in how participants conceptualized these incidents. First, participants understood trust as performative vulnerability: trust was necessary to sustain relationships, but building trust required displaying vulnerability to breaches. Second, participants were self-serving in their sensemaking: they blamed the circumstances, or the other person's shortcomings, but rarely themselves. We discuss the implications of our findings for security design and practice.

Facebook accounts are secured against unauthorized access through passwords and device-level security. Those defenses, however, may not be sufficient to prevent social insider attacks, where attackers know their victims, and gain access to a victim's account by interacting directly with their device. To characterize these attacks, we ran two MTurk studies. In the first (n = 1,308), using the list experiment method, we estimated that 24% of participants had perpetrated social insider attacks and that 21% had been victims (and knew about it). In the second study (n = 45), participants wrote stories detailing personal experiences with such attacks. Using thematic analysis, we typified attacks around five motivations (fun, curiosity, jealousy, animosity, and utility), and explored dimensions associated with each type. Our combined findings indicate that social insider attacks are common, often have serious emotional consequences, and have no simple mitigation.

Accessibility research studies often gather subjective responses to technology using Likert-type items, where participants respond to a prompt statement by selecting a position on a labeled response scale. We analyzed recent ASSETS papers, and found that participants in non-anonymous accessibility research studies gave more positive average ratings than those in typical usability studies, especially when responding to questions about a proposed innovation. We further explored potential positive response bias in an experimental study of two telephone information systems, one more usable than the other. We found that participants with visual impairment were less sensitive to usability problems than participants in a typical student sample, and that their subjective ratings didn't correlate as strongly with objective measures of performance. A deeper understanding of the mechanism behind this effect would help researchers to design better accessibility studies, and to interpret subjective ratings with more accuracy.

Despite the overwhelming emergence of accessible digital technologies, Braille still plays a role in providing blind people with access to content. Nevertheless, many fail to see the benefits of nurturing Braille, particularly given the time and effort required to achieve proficiency. Our research focuses on maximizing access and motivation to learn and use Braille. We present initial insights from 5 interviews with blind people, comprising of Braille instructors and students, where we characterize the learning process and usage of Braille. Based on our findings, we have identified a set of opportunities around Braille education. Moreover, we devised scenarios, and built hardware and software solutions to motivate discovery and retention of Braille literacy.