SNOUT:
One-Handed use of Capacitive Touch Devices
Adam Zarek, Daniel Wigdor, Karan Singh
University of Toronto
Problem
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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.
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Touch-free Alternatives
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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
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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
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Design Goals
•
Minimize nose taps
•
Minimize nose sliding
•
Avoid inducing eye-fatigue
•
Preserve existing UI layouts
•
Mitigate interaction errors
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SNOUT Design
• Selection
• Text Entry
• Continuous parameter specification
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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
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SNOUT selection
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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
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SNOUT text entry
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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
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SNOUT continuous parameters
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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)
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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.
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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
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Quantitative Results
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Message
• Peripheral feedback has general UI potential
• Potential as accessability interface.
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Thank you!
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