GestureCalc: An Eyes-Free Calculator for Touch Screens

B. Chaudhuri et al., “GestureCalc: An Eyes-Free Calculator for Touch Screens,” in International ACM SIGACCESS Conference on Computers and Accessibility, New York, NY, USA, 2019, pp. 112–123, doi: 10.1145/3308561.3353783.


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 that are time-consuming and error-prone for many screen readers users. We introduce GestureCalc, a digital calculator that uses target-free gestures for arithmetic tasks. It allows eyes-free target-less input of digits and operations through taps and directional swipes with one to three fingers, guided by minimal audio feedback. 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 and 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.

BibTeX Entry

  title = {GestureCalc: An Eyes-Free Calculator for Touch Screens},
  author = {Chaudhuri, Bindita and Perlmutter, Leah and Petelka, Justin and Garrison, Philip and Fogarty, James and Wobbrock, Jacob O. and Ladner, Richard E.},
  year = {2019},
  booktitle = {International ACM SIGACCESS Conference on Computers and Accessibility},
  location = {Pittsburgh, PA, USA},
  publisher = {ACM},
  address = {New York, NY, USA},
  series = {ASSETS '19},
  pages = {112--123},
  doi = {10.1145/3308561.3353783},
  isbn = {978-1-4503-6676-2},
  url = {},
  type = {conference},
  numpages = {12},
  acmid = {3353783},
  keywords = {digital calculator, eyes-free entry, gesture input, mobile devices, touch screen}