Evaluation of Viewport Size and Curvature of Large, High-Resolution Displays

Lauren Shupp, Robert Ball, John Booker, Beth Yost, Chris North

Virginia Polytechnic and State University

Center for Human Computer Interaction, Department of Computer Science

http://infovis.cs.vt.edu

Outline Motivation & Related Work

Experimental Design

Results & Observations

Conclusions & Impact

Questions

Related Work Physical construction

Mark Hereld, Ivan R. Judson and Rick L. Stevens. Tutorial: Introduction to building project-based tiled display systems

Software for distributing the graphicsGreg Humphreys, et. al. Chromium: A stream-processing framework for interactive rendering on clusters

Most usability research is for collaborationScott Elrod, et. al. Liveboard: A large interactive display supporting group meetings, presentations, and remote collaboration.

Related Work Partitioned spaces vs. one large space

Jonathan Grudin. Partitioning digital worlds: Focal and peripheral awareness in multiple monitor use.

Larger displays narrow gender gap on spatial performanceMary Czerwinski, Desney Tan and George Robertson. Women take a wider view.

Focus+Context screensPatrick Baudisch, Nathaniel Good, Victoria Bellotti and Pamela Schraedley. Keeping things in context: A comparative evaluation of focus plus context screens, overviews, and zooming.

Related Work Large (3x3) high-resolution (3840×3072)

displays can result in better performance than panning and zooming on smaller displaysRobert Ball and Chris North. Effects of tiled high-resolution display on basic visualization and navigation tasks.

Motivation: ViewportIs bigger (viewport) better? Is there a display that is too big?

More detailed data & more context at once

(3072 x 10,240)

Physical navigation using eye, head, and body movement

Motivation: CurvatureWhat happens if we curve the display?

Reduce time physically navigating

Change physical navigation to less strenuous turning rather than walking

Motivation: Curvature

All pixels are resolvable using only head and eye movements

(2.75 times more resolvable pixels on our 24 monitor display)

Experimental Design Independent variable: display condition

Dependent variables: time, accuracy, and mental-workload (mental demand, physical demand, effort, and frustration)

Flat Curved

1 monitor

12 monitors

24 monitors

8 users in each (40 total)

Experimental DesignFactor Level

viewport {1 monitor12 monitors24 monitors

between subject

curvature { flatcurved

between subject

task type {searchroute tracingimage comparison

within subject

task difficulty { easyhard

within subject

Tasks Search

Route Tracing

portion of Expressway 402 East of Atlanta, GA (labeled Highway 8)

Tasks Route Tracing

Tasks Image comparison

ResultsOverall Completion Times

0

50

100

150

200

1 mon 12 flat 12curved

24 flat 24curved

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Suggests both larger viewport sizes and curvature improve user performance times

Results: Task SpecificEasy Route Task

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1 mon 12 flat 12curved

24 flat 24curved

Com

plet

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Tim

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Easy Search Task

0204060

80100120140

1 mon 12 flat 12curved

24 flat 24curved

Com

plet

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Tim

e (s

)

Both the 12 and 24 monitor conditions improve performance over one monitor (approximately 2-6 times faster)

For route tasks, the 24 monitor condition improves performance over the 12 monitor condition (approximately 50% faster)

Results: Task Specific

Curvature for Easy Tasks

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flat curved

Co

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(s)

Viewport Size for Easy Tasks

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route search

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Curved displays improve performance over flat displays independently of viewport size

For route tasks, the 24 monitor condition improves performance over the 12 monitor condition (approximately 50% faster)

ResultsFrustration

0%10%20%30%40%50%60%70%80%

1 mon 12 flat 12curved

24 flat 24curved

Observations Viewport Size

One monitor used significantly more virtual navigation (pan & zoom)

12 and 24 monitor used more physical navigation (standing, walking, leaning)

Strategies changed by second Image comparison task (switch from serial pattern to overview target)

Observations Curvature

Change in physical navigation Flat: standing (5/8), walking Curved: body and head turns

Keyboard and mouse may have hindered users on the flat display from walkingmore

Users changed their area of focus more frequently on the curved 24 monitor condition

Conclusions Larger viewport sizes improve performance

Search: 12 better than 1 mon Route: 24 better than 12 mon

Larger viewport sizes reduce virtual navigation and increase physical navigation

Larger viewport sizes yield less frustration Curved displays improve performance time

Physical navigation changes from standing and walking to turning when the display is curved

Impact 24 monitor display is not too big!

Curve large displays for single users

Questions

?Virginia Polytechnic and State University

Center for Human Computer Interaction, Department of Computer Science

http://infovis.cs.vt.edu