This document summarizes a study investigating back-to-front pinching for eyes-free mobile touch input. The study tested how factors like device thickness and target location affect pinching errors. It collected data from 18,000 pinches across different thicknesses and angles. The results showed that thickness and target location have a main effect on error, with error increasing with thickness and moving along a curve for off-center targets. Limitations included not varying digitizer size, but future work could explore learning algorithms.

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Presented by : Nafees Ahmed
Supervised By : Dr. Shah Rukh Humayoun
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Understanding Back-to-Front Pinching for Eyes-Free
Mobile Touch Input
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 HaptiCase
 Phone protection case with tactile landmark at the back correspond the size and
position of apposed touch screen
Overview
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 To Understand which factors lead to an Error
 Device thickness
 Tilt angle
 Target Location on the pinch error
Our Goal
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 Mapping Error
 User may not map the location of the distant target to the back of the phone
precisely, resulting in a mapping Error
 Pinching Errors
 Thumb and finger position may not match.
Errors
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 PinchPad: Performance of Touch-Based Gestures while Grasping Devices
 focuses on combining front and back device interaction on grasped devices, using
touch-based gestures
 combined two iPads together back-to-back and test touch-based interactions
 Limitations
 In PinchPad the offset was not quantified it means that an offset along the
horizontal axis between the thumb at the front and the other fingers at the back
of the device were not matched their position.
 Thickness was also a big issue for an accurate pinching.
Related Work
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 Two touch digitizers 5”
 Shielding 2,0mm
 Cardboard Slice 18g
 Tactile landmarks
 5 Thickness 4 angles
Experiment Design
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Results
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 Collection of 18,000 pinches are studied
 Three factors
 (H1) Distribution of touches around targets at the back differ widely from those
pinched at the front.
 (H2) Thickness have a main effect on ERROR. Error increases for both x and y with
increasing thickness.
 (H3) With increasing “ANGLE” pinches move along a curve at the lower left for
targets at the left resp.
 (H4) Target also have a main effect on Error
Results
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Results
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Results
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 Didn’t Vary the size of Digitizers
 Future Work
 Learning algorithms
Limitations
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 Title of the paper doesn’t clearly reflect the content of the paper
 The location on the screen could properly touched with some practice and
learning while trying to touch the respective location of the finger on the back
Own Evaluation
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Investigating the Effects of Splitting Detailed
Views in Overview+Detail Interface
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 Interfaces:
 Detail View
 Overview + Detail View(O+D)
About
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 Need of Overview + Detail View
 Details view cumbersome
 Difficulty increased when working on multiple regions.
 Purpose
 To find of usability of Multiple view vis-a-vie Single view
 To support study with working via graphical nodes
Need & Purpose of Study
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 Topology of Links
 Do not support simultaneous working viz., Multi display etc.
 Multi- Screen
 Helps in case of large contexts such as geographical data
 Rotation of object position preferred
 Multi-Focus Screen
 Distortion Technique used
 Multi touch interaction help in folding data manifold
Related Work
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 Molecular Interaction Maps(MIM)
 Interaction technology
 Helps utilizing detailed views
Related Work (cont.)
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 O + D interface is deployed in design detailed view interface
 Classified into three views:
 Split View
 Helps in understanding screen area and dividing it into parts
 Overview
 Translation
 Representation of positive view on overview
Interface Design
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 Views
 Splits a view further into sub views:
 1 view
 2 view
 4 view
 Easy to focus
Split Views
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Split Views
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 Views:
 Displays the entire graph on larger display
 Ratios with Split Views:
 9 for 1 view configuration
 18 for 2 view configuration
 36 for 4 view configuration
Overviews
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 Views:
 Translates overview of a split view into View Icon based on the positioning.
 Working with views:
 Position can be adjusted with direct screen manipulation
 Multi touch supported
Translation View
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 Experiment Conducted:
 Conducted to check effects of multiple detailed views.
 Task was to identify node positions which were translated and then selecting them
through the split views.
 Apparatus:
 Tablet and one PC.
 Working with set up:
 Participants were told to press a button in the center of the screen which used to get
refreshed, a multi touch set up.
Experiment & Results
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 Results
 Measured data:
 Completion Time
 Simultaneous Icons Translation
 Number of switches between overview and split view
 The result is consolidated in the next slide.
Experiment & Results
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Experiment & Results – Completion Time
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Experiment & Results – Switches/Icons
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 Limitations:
 Changing position of root nodes
 Pros:
 Multi Detailed View:
 More view at one place
 Multi comparison
Evaluation
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 Modifiable:
 Split screens can be modified according to personal needs viz., with the dimensions.
 Split View:
 Number of views can be increased.
Future Work
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THANK YOU ALL
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