SNOUT: One-Handed use of Capacitive Touch Devices Adam Zarek, Daniel Wigdor, Karan Singh University of Toronto

2 Problem

3 Exploring the solution space Survey: We presented 6 scenarios where conventional finger input was not possible, seeking input alternatives. …wearing gloves, dirty or preoccupied hands. 15 participants (13 male, 12 owning a touch device). Results: 86% of participants suggested the non-conventional appendages: nose, toe, elbow, knuckle at least once. the nose provided the broadest coverage across participants, 60% suggesting it in at least one scenario.

4 Touch-free Alternatives

5 Nose Pilot Study How accurate is nose-based interaction? 8 participants (7 male, all familiar with touch devices) Results: Mean miss distance from the target was 0.43 times the target size  Target size should be scaled by 1.5x the target width 4/5mm 8/11mm 12/15mm

6 Design Principles from pilot study Avoid sliding since will dirty the screen UI elements must be “large enough” Focusing on what the nose is currently touching induces eye-fatigue Avoid repeated up-down motions

7 Design Goals Minimize nose taps Minimize nose sliding Avoid inducing eye-fatigue Preserve existing UI layouts Mitigate interaction errors

8 SNOUT Design Selection Text Entry Continuous parameter specification

9 SNOUT selection Increase target size by 1.5x (pilot study) Reduce reliance on focused visual feedback Solution: Two-stage color-based selection Pre-processing: split UI into Voronoi regions apply cyclic color patterns step 1: aim for the selection target flooding the periphery with the color of the currently selected region step 2: slide nose on screen until the color of the desired selection is on the periphery, then disengage

10 SNOUT selection

11 SNOUT text entry Small keyboard Single appendage No visual focus on selection => repeated key selection cumbersome Augment color-based selection with speech recognition Tapping a text box launches speech recognition service Corrections are made using color-based selection

12 SNOUT text entry

13 SNOUT continuous parameters No visual focus Minimize sliding => direct touch manipulation is difficult Control the parameter by tilting the device Enter tilt mode via touch-and-tap gesture Exit tilt mode via hardware volume buttons Touch-and-tap: hold the device to your nose and then tap on the back of the device

14 SNOUT continuous parameters

15 Usability Study Method: 3 custom applications that use our interaction techniques Asked to accomplish a set of tasks within each application Before/after survey about willingness to use different body parts as input methods Participants: 12 participants (9 male, 22-35, all with mobile experience)

16 Applications Application Launcher: selection and scrolling Launch 5 applications at different screen locations including scrolling Notepad: speech to text and keypad selection Text input of at least 10 characters and less than 3 characters. Text input of varying length using both text entry methods. Map Browser: scrolling and zooming Map navigation exercise, viewing a round trip of checkpoints in Cambridge MA, Mexico City, Tokyo.

17 Qualitative Results Peripheral color based selection Generally successful, works well in practice Overhead of keeping target color in memory Works better when focus is on color than tip of nose Text entry Generally preference for text to speech Direct selection useable for short messages Additional support for word-level selection desired Continuous parameters Touch+tap is an easily performed gesture Works as well/poorly as tilt based parameter control Some users attempted to use typical sliding motions

18 Quantitative Results

19 Message Peripheral feedback has general UI potential Potential as accessability interface.

20 Thank you!