GestureCalc: An Eyes-Free Calculator for Touch Screens
Published in The 21st International ACM SIGACCESS Conference on Computers and Accessibility, 2019
Chaudhuri, B., Perlmutter, L., Petelka, J., Garrison, P., Fogarty, J., Wobbrock, J. O., & Ladner, R. E. (2019). "GestureCalc: An Eyes-Free Calculator for Touch Screens". In The 21st Interactional ACM SIGACCESS Conference on Computers and Accessibility. https://doi.org/10.1145/3308561.3353783
Abstract - A digital calculator is one of the most frequently used touch screen applications. However, keypad-based character input in existing calculator applications requires precise, targeted key presses, which is time consuming and error-prone for screen readers users. We introduce GestureCalc, a digital calculator that uses target-free gestures for arithmetic tasks. It allows eyes-free input in the form of taps and directional swipes with one to three fingers, guided by minimal audio feedback, to enter digits and operations. We conducted a mixed methods longitudinal study with eight screen reader users and found that they entered characters with GestureCalc 40.5% faster on average than with a typical touch screen calculator. Participants made more mistakes but also corrected more errors with GestureCalc, resulting in 52.2% fewer erroneous calculations than the baseline. Over the three sessions in the study participants were able to learn the GestureCalc gestures well to efficiently perform short calculations. From our interviews after the second session, participants recognized the effort in learning a new gesture set, yet reported confidence in their ability to become fluent in practice.