SNOUT: One-Handed use of Capacitive Touch Devices

Adam Zarek, Daniel Wigdor, Karan Singh

University of Toronto

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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 sizeTarget 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!