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

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 graphics Greg Humphreys, et. al. Chromium: A stream-processing framework for interactive rendering on clusters  Most usability research is for collaboration Scott 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.  Horizontal monitors as separate rooms and vertical as single spaces Robert Ball and Chris North. An analysis of user behavior on high-resolution tiled displays.  Larger displays narrow gender gap on spatial performance Mary Czerwinski, Desney Tan and George Robertson. Women take a wider view.  Focus+Context screens Patrick 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 displays Robert Ball and Chris North. Effects of tiled high-resolution display on basic visualization and navigation tasks.

Motivation: Viewport Is 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: Curvature What 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) FlatCurved 1 monitor 12 monitors 24 monitors 8 users in each (40 total)

Experimental Design FactorLevel viewport { 1 monitor 12 monitors 24 monitors between subject curvature { flat curved between subject task type { search route tracing image comparison within subject task difficulty { easy hard within subject

Tasks  Search

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

Tasks  Route Tracing

Tasks  Image comparison

Results Suggests both larger viewport sizes and curvature improve user performance times

Results: Task Specific 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 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)

Results

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 walking more 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