Diogo Marques

Privacy and secrecy in ubiquitous text messaging

This paper presents a study on privacy and secrecy requirements that users feel while in the presence of other people. They are viewed as issues of a social activity and pertain to the desire that the content of messages or the act of writing or reading them is not perceived by others. We assess the needs for privacy according to the messages themes and acquaintance type with the recipient. We also present and discuss our findings considering user strategies in coping with the required privacy using both a quantitative and a qualitative approach. The study results show clearly the need to consider those requirements in the design of messaging applications for mobile devices. Circa 50% of the messages analyzed required privacy on the act of writing/reading. The reasons are multifaceted and vary according to the addressees and the content type reaching 70% for specific cases. We close the paper, with a proposal of a personal, multimodal and inconspicuous communication framework, which not only allows users to define their vocabulary, but also entry and output methods from a range of different modalities.

Measuring snooping behavior with surveys: it's how you ask it

In close relationships, snooping on anothers mobile device is commonly regarded as an invasion of privacy. The prevalence of such behavior is, however, difficult to assess. We compared two in-person survey techniques, one in which the question about snooping behavior is posed directly, and one in which strong anonymity controls are employed. Results (n=90) reveal that, while in the first case 10% of respondents admitted to snooping, in the second the estimate was 60%. This shows that, although there is a potent social desirability bias at play, strong anonymity controls do improve estimates. Furthermore, it suggests an alarming prevalence of snooping behavior among the target population.

Augmenting braille input through multitouch feedback

Current touch interfaces lack the rich tactile feedback that allows blind users to detect and correct errors. This is especially relevant for multitouch interactions, such as Braille input. We propose HoliBraille, a system that combines touch input and multi-point vibrotactile output on mobile devices. We believe this technology can offer several benefits to blind users; namely, convey feedback for complex multitouch gestures, improve input performance, and support inconspicuous interactions. In this paper, we present the design of our unique prototype, which allows users to receive multitouch localized vibrotactile feedback. Preliminary results on perceptual discrimination show an average of 100% and 82% accuracy for single-point and chord discrimination, respectively. Finally, we discuss a text-entry application with rich tactile feedback.

The today and tomorrow of Braille learning

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.

Characterizing Social Insider Attacks on Facebook

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 victims 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.

Optimus web: selective delivery of desktop or mobile web pages

We propose a system that selectively delivers the most accessible representations of a website to the end-user. To do so, we resort to a Web proxy that, using the results of an automatic evaluator, changes HTTP requests and delivers the most suitable available representation. The accessibility evaluator uses WCAG 2.0 [1] guidelines and considers pages after browser interpretation. We performed a user study with 19 blind participants where different representations of website were used. Results show that user performance correlates with the computed accessibility levels, and that for different websites either mobile or desktop versions may turn out to be more accessible. Expert users seem to perform independently from the level of accessibility of the pages. These results suggest that a proxy that selectively delivers Web page representations is feasible and that future work should also consider the profile of the user for selection.

LOST-Map: A Victim-Sourced Rescue Map of Disaster Areas

In the aftermath of natural disasters, members of the affected communities are often the de facto first responders. Local volunteers can respond quickly, are strongly motivated, and have the necessary ground knowledge. However, their search and rescue efforts may be misdirected in the absence of information about the location and status of victims. We propose LOST, a system that gathers data from smartphones in affected areas, even when the regular communication infrastructure fails, and aggregates it in a web interface for visualization. For each individual, LOST-Map shows location traces and activity indicators. The information can be explored by selecting time-frames and/or applying filters over activity indicators. This paper briefly describes the design of LOST, introduces the visualization tool LOST-Map, and reports on a study (n=10) that suggests that it can be effectively used by untrained volunteers.

Workshop on inconspicuous interaction

Growing usage of interactive systems in the public space has highlighted the prevalence of conflicts between desired functionality and maintenance of privacy/social comfort. This has inspired researchers and practitioners, in communities concerned with usable security, wearable and mobile interfaces, natural user interfaces, accessibility and social interaction, to employ inconspicuous interaction styles. This workshop will bring these communities together to produce forward-looking insights that can shape the way users interact with tomorrows computers, in interactive systems that account for the social nomadic contexts where they are bound to be used.