Multidimensional Pareto optimization of touchscreen keyboards for speed, familiarity and improved spell checking

The paper presents a new optimization technique for keyboard layouts based on Pareto front optimization. We used this multifactorial technique to create two new touchscreen phone keyboard layouts based on three design metrics: minimizing finger travel distance in order to maximize text entry speed, a new metric to maximize the quality of spell correction quality by minimizing neighbouring key ambiguity, and maximizing familiarity through a similarity function with the standard Qwerty layout. The paper describes the optimization process and resulting layouts for a standard trapezoid shaped keyboard and a more rectangular layout. Fitts' law modelling shows a predicted 11% improvement in entry speed without taking into account the significantly improved error correction potential and the subsequent effect on speed. In initial user tests typing speed dropped from approx. 21wpm with Qwerty to 13wpm (64%) on first use of our layout but recovered to 18wpm (85%) within four short trial sessions, and was still improving. NASA TLX forms showed no significant difference on load between Qwerty and our new layout use in the fourth session. Together we believe this shows the new layouts are faster and can be quickly adopted by users

Predicting and Reducing the Impact of Errors in Character-Based Text Entry

This dissertation focuses on the effect of errors in character-based text entry techniques. The effect of errors is targeted from theoretical, behavioral, and practical standpoints. This document starts with a review of the existing literature. It then presents results of a user study that investigated the effect of different error correction conditions on popular text entry performance metrics. Results showed that the way errors are handled has a significant effect on all frequently used error metrics. The outcomes also provided an understanding of how users notice and correct errors. Building on this, the dissertation then presents a new high-level and method-agnostic model for predicting the cost of error correction with a given text entry technique. Unlike the existing models, it accounts for both human and system factors and is general enough to be used with most character-based techniques. A user study verified the model through measuring the effects of a faulty keyboard on text entry performance. Subsequently, the work then explores the potential user adaptation to a gesture recognizer’s misrecognitions in two user studies. Results revealed that users gradually adapt to misrecognition errors by replacing the erroneous gestures with alternative ones, if available. Also, users adapt to a frequently misrecognized gesture faster if it occurs more frequently than the other error-prone gestures. Finally, this work presents a new hybrid approach to simulate pressure detection on standard touchscreens. The new approach combines the existing touch-point- and time-based methods. Results of two user studies showed that it can simulate pressure detection more reliably for at least two pressure levels: regular (~1 N) and extra (~3 N). Then, a new pressure-based text entry technique is presented that does not require tapping outside the virtual keyboard to reject an incorrect or unwanted prediction. Instead, the technique requires users to apply extra pressure for the tap on the next target key. The performance of the new technique was compared with the conventional technique in a user study. Results showed that for inputting short English phrases with 10% non-dictionary words, the new technique increases entry speed by 9% and decreases error rates by 25%. Also, most users (83%) favor the new technique over the conventional one. Together, the research presented in this dissertation gives more insight into on how errors affect text entry and also presents improved text entry methods

Survey of Eye-Free Text Entry Techniques of Touch Screen Mobile Devices Designed for Visually Impaired Users

Now a days touch screen mobiles are becoming more popular amongst sighted as well visually impaired people due to its simple interface and efficient interaction techniques. Most of the touch screen devices designed for visually impaired users based on screen readers, haptic and different user interface (UI).In this paper we present a critical review of different keypad layouts designed for visually impaired users and their effect on text entry speed. And try to list out key issues to extend accessibility and text entry rate of touch screen devices.Keywords: Text entry rate, touch screen mobile devices, visually impaired users

Ergonomic, adaptable keyboard for fast data entry on mobile computing devices

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.Includes bibliographical references (leaves 22-24).The usefulness of modem portable computational devices such as cellular phones and portable digital assistants (PDAs) is currently limited by the lack of an effective method for text entry. The currently available input options (such as the 12-key phone pad and PDA touch screens) are a quarter to a third of the speed of the standard desktop QWERTY keyboards. Therefore, it is slow and frustrating for people to use these systems for any significant text input, such as writing emails, taking notes in a meeting, or writing down thoughts while on-the-go. The proposed solution is a one-handed, hand-held, wireless, portable keyboard that would allow the mobile device user to achieve speeds closer to the desktop standard while performing text-entry tasks. Previously developed handheld input devices employ unfamiliar typing systems, are too large, or are not ergonomically comfortable, which may be the reasons they have not been widely adopted by the public. The device described in this paper is small enough to store in one's pocket, is inconspicuous during use, and is adjustable so that the keys reach the fingers in their natural curved position. One interface point allows each finger to control multiple buttons thereby preventing the fingers from, needing to move into uncomfortable positions.(cont.) These features were incorporated into a prototype that proves the feasibility of a compact and comfortable hand-held keyboard. The device also has potential as an ergonomic replacement to the standard desktop keyboard. Unlike traditional keyboards it allows the typist to be relaxed and mobile eliminating some risk factors for repetitive strain injury.by Alexander Mekelburg.S.B

Towards Baselines for Shoulder Surfing on Mobile Authentication

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, improving to 26.5\% with multiple observations. As a comparison, 6-length Android patterns, with one observation, suffered 64.2% attack rate and 79.9% with multiple observations. Removing feedback lines for patterns improves security from 35.3\% and 52.1\% for single and multiple observations, respectively. 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.Comment: Will appear in Annual Computer Security Applications Conference (ACSAC

Towards high quality text entry on smartwatches

Smartwatches now provide users with access to many applications on smartphones direct from their wrists, without the need to touch their smartphone. While applications such as email, messaging, calendar and social networking provide views on the watch, there is normally no text entry method so users cannot reply on the same device. Here we introduce requirements for smartwatch text entry, an optimised alphabetic layout and present a prototype implementation together with preliminary user feedback. While raising some problems, the feedback gives indicates that reasonable quality and speed is achievable on a smartwatch and encourages our future work

Designed with older adults to support better error correction in smartphone text entry : the MaxieKeyboard

Through our participatory design with older adults a need for improved error support for texting on smartphones emerged. Here we present the MaxieKeyboard based on the outcomes from this process. The keyboard highlights errors, auto-corrections and suggestion bar usage in the composition area and gives feedback on the keyboard on typing correctness. Our older adult groups have shown strong support for the keyboard