Tiago João Vieira Guerreiro

BrailleType: unleashing braille over touch screen mobile phones

The emergence of touch screen devices poses a new set of challenges regarding text-entry. These are more obvious when considering blind people, as touch screens lack the tactile feedback they are used to when interacting with devices. The available solutions to enable non-visual text-entry resort to a wide set of targets, complex interaction techniques or unfamiliar layouts. We propose BrailleType, a text-entry method based on the Braille alphabet. BrailleType avoids multi-touch gestures in favor of a more simple single-finger interaction, featuring few and large targets. We performed a user study with fifteen blind subjects, to assess this methods performance against Apples VoiceOver approach. BrailleType although slower, was significantly easier and less error prone. Results suggest that the target users would have a smoother adaptation to BrailleType than to other more complex methods.

Typing Performance of Blind Users: An Analysis of Touch Behaviors, Learning Effect, and In-Situ Usage

Non-visual text-entry for people with visual impairments has focused mostly on the comparison of input techniques reporting on performance measures, such as accuracy and speed. While researchers have been able to establish that non-visual input is slow and error prone, there is little understanding on how to improve it. To develop a richer characterization of typing performance, we conducted a longitudinal study with five novice blind users. For eight weeks, we collected in-situ usage data and conducted weekly laboratory assessment sessions. This paper presents a thorough analysis of typing performance that goes beyond traditional aggregated measures of text-entry and reports on character-level errors and touch measures. Our findings show that users improve over time, even though it is at a slow rate (0.3 WPM per week). Substitutions are the most common type of error and have a significant impact on entry rates. In addition to text input data, we analyzed touch behaviors, looking at touch contact points, exploration movements, and lift positions. We provide insights on why and how performance improvements and errors occur. Finally, we derive some implications that should inform the design of future virtual keyboards for non-visual input.

B#: chord-based correction for multitouch braille input

Braille has paved its way into mobile touchscreen devices, providing faster text input for blind people. This advantage comes at the cost of accuracy, as chord typing over a flat surface has proven to be highly error prone. A misplaced finger on the screen translates into a different or unrecognized character. However, the chord itself gathers information that can be leveraged to improve input performance. We present B#, a novel correction system for multitouch Braille input that uses chords as the atomic unit of information rather than characters. Experimental results on data collected from 11 blind people revealed that B# is effective in correcting errors at character-level, thus providing opportunities for instant corrections of unrecognized chords; and at word-level, where it outperforms a popular spellchecker by providing correct suggestions for 72% of incorrect words (against 38%). We finish with implications for designing chord-based correction system and avenues for future work.

Blind People Interacting with Large Touch Surfaces: Strategies for One-handed and Two-handed Exploration

Interaction with large touch surfaces is still a relatively infant domain, particularly when looking at the accessibility solutions offered to blind users. Their smaller mobile counterparts are shipped with built-in accessibility features, enabling non-visual exploration of linearized screen content. However, it is unknown how well these solutions perform in large interactive surfaces that use more complex spatial content layouts. We report on a user study with 14 blind participants performing common touchscreen interactions using one and two-hand exploration. We investigate the exploration strategies applied by blind users when interacting with a tabletop. We identified six basic strategies that were commonly adopted and should be considered in future designs. We finish with implications for the design of accessible large touch interfaces.

TabLETS Get Physical: Non-Visual Text Entry on Tablet Devices

Tablet devices can display full-size QWERTY keyboards similar to the physical ones. Yet, the lack of tactile feedback and the inability to rest the fingers on the home keys result in a highly demanding and slow exploration task for blind users. We present SpatialTouch, an input system that leverages previous experience with physical QWERTY keyboards, by supporting two-handed interaction through multitouch exploration and spatial, simultaneous audio feedback. We conducted a user study, with 30 novice touchscreen participants entering text under one of two conditions: (1) SpatialTouch or (2) mainstream accessibility method Explore by Touch. We show that SpatialTouch enables blind users to leverage previous experience as they do a better use of home keys and perform more efficient exploration paths. Results suggest that although SpatialTouch did not result in faster input rates overall, it was indeed able to leverage previous QWERTY experience in contrast to Explore by Touch.

Friendsourcing the unmet needs of people with dementia

The decay of cognitive abilities associated with dementia severely impacts the quality of life of a person and his surrounding ecosystem. First, people with dementia (PwD) increasingly forget the events in their lives leading to depression, isolation and faster cognitive deterioration. Second, their caregivers, besides the emotional burden that having someone close in such a condition carries, are also likely to be overwhelmed with responsibilities and duties in maintaining the PwD with a balanced and decent lifestyle. Our approach tries to address this by providing a prosthetic memory captured in two ways: 1) automatically captures data from the PwDs smartphone and enriches it with automatically retrieved data from the web and, 2) a private social network group (friendsourcing) used to validate and personalize the relevant events in the PwDs life. By sharing the load among a limited but still populated set of trustworthy people we aim to maintain the caregiving process feasible and maintain more people engaged with the PwD. Overall, the ultimate goal is to provide reminiscence, safety and cognitive aids for the PwD that are up-to-date and personally relevant.

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.

TinyBlackBox: Supporting Mobile In-The-Wild Studies

Most work investigating mobile HCI is carried out within controlled laboratory settings; these spaces are not representative of the real-world environments for which the technology will predominantly be used. The result of which can produce a skewed or inaccurate understanding of interaction behaviors and users-- abilities. While mobile in-the-wild studies provide more realistic representations of technology usage, there are additional challenges to conducting data collection outside of the lab. In this paper we discuss these challenges and present TinyBlackBox, a standalone data collection framework to support mobile in-the-wild studies with today--s smartphone and tablet devices.