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i247: Information Visualization and Presentation Marti Hearst. April 16, 2008. Today. 3D visualization 3D in scientific visualization Applying 3D to abstract data The PARC Information Visualizer and follow-ons 3D for data graphics Navigating in 3D space The debate: does 3D help?
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i247: Information Visualization and PresentationMarti Hearst April 16, 2008
Today • 3D visualization • 3D in scientific visualization • Applying 3D to abstract data • The PARC Information Visualizer and follow-ons • 3D for data graphics • Navigating in 3D space • The debate: does 3D help? • Cognitive abilities and 3D • 3D vs 2D • Case Study: Helping Helicopter Pilots (scientific viz)
3D and Scientific Visualization • Visualizing information that is inherently 3D is a special case of infoviz • “Easier” in the sense that the 3D inherently makes sense • Still, you need to choose what to show and what not to show. • Images from https://graphics.llnl.gov/flow.html
3D for Abstract Information • Pioneering Work by Card and Robertson • Had state-of-the-art graphics hardware; wanted to see what happens when pushing the boundaries • Motivated by Card & Moran’s theories of cognitive architecture • Information Visualizer (PARC) • WebBook/Webforager (PARC, 1996) • Data Mountain (MS Research, 1998) • Task Gallery (MS Research, 2000)
Information Workspaces • Objective: • Decrease the costs for performing information-intensive tasks, or, alternatively, increase the scope of information that can be utilized for the same cost. • Method: • Large Workspaces • Make the immediate workspace virtually larger • Real-Time Interaction • Maximize the interaction rates • Visual Abstractions • Speed assimilation and pattern detection 8
Information Visualizer 17 research.microsoft.com/~ggr/gi97.ppt
Web Forager http://research.microsoft.com/ui/TaskGallery/index.htm 24
Task Gallery (Robertson et al. 2000) http://research.microsoft.com/ui/Taskgallery/pages/video.htm 23
Robertson, Czerwinski et al, 1998 Follow-on to Information Visualizer Organizing bookmarks using pile metaphor Uses: Spatial organization 3D view with 2D interaction Cartoon animation details Subtle audio cues Debate: Is this better than 2D? Data Mountain http://research.microsoft.com/adapt/datamountain/video/datamtn.mpeg
3D vs. 2D • Cockburn & McKenzie ’02 • Results for prior work with 3D systems are primarily negative for viz of things that are not inherently in 3D, but really results are mixed • Compared 2D, 2½D and 3D views of web page thumbnails • Did this for both physical and virtual interfaces • Compared sparse, medium, and dense displays
3D vs. 2D • Cockburn & McKenzie ’02 • Results: • Time taken sig. increased through 2D -> 3D interfaces • Subjective assessment sig. decreased 2D -> 3D • Performance degraded with denser problems • 3D virtual interface produced the slowest times • People prefered the physical interfaces • People were better at using their spatial memory than they expected to be • There was a problem with the physical 2½D display
The Role of Cognitive Abilities • Leitheiser & Munro ‘95 • Summarizes the results of earlier psychological research on spatial aptitiude • Also summarizes work on effects of spatial aptitude and UI use • Presents a study comparing a GUI with a command line interface, taking spatial abilities into account
The Role of Cognitive Abilities • Leitheiser & Munro ’95 • Hypotheses: • Users with high spatial ability would benefit more from the GUI than those with low spatial ability (H1) • Users with high verbal ability would perform better on command line interfaces (H2) • Tasks: • Obtain system time, list files, look up a file update time, open a subdirectory, move a file, copy a file, etc • Between subjects GUI (Mac) vs. Command line (DOS) • Findings: • H1 supported • H2 not supported • Everyone did better on the GUI • Low spatial ability users using the GUI required 90% of the time needed for command line interface
Gender differences and 3D • Previous studies often found gender differences in 3D navigation • Czerwinski et al. wondered why; saw a hint in one study, did a followup study in detail • Idea: change the assumptions • Make screen wider • Gender performance differences disappear • Both improved
3D and Data Graphics • There have been lots of attempts to 3D-ify these • Results seemed mixed • Some modern versions of the ideas are here: • http://www.oculusinfo.com/demos.html • http://www.oculusinfo.com/softwareproducts.html
Interacting with 3D spaces • Path-drawing for 3D walkthrough, • Igarashi et al, UIST ’98 • Problem: interacting with 3D via 2D screens • Solution: be clever about how to convert 2D to 3D based on what the user is likely to intend http://www-ui.is.s.u-tokyo.ac.jp/~takeo/video/navi.mpg
Creating in 3D Spaces • Teddy: A 3D Drawing System • Igarishi 1999 http://www-ui.is.s.u-tokyo.ac.jp/~takeo/video/teddy.avi http://www-ui.is.s.u-tokyo.ac.jp/~takeo/teddy/teddy/teddy.html
Other 3D Creation Tools • Lots of other great ideas from Igarashi’s lab: • http://www-ui.is.s.u-tokyo.ac.jp/projects/index.html
Sequences of Steps vs 3D + Animation • Heiser, Phan, Agrawala, Tversky, Hanrahan ‘04 • Domain: assembly instructions • Identify • How people conceive of 3D assemblies • How people comprehend visual instructions • Validate • Build automated instruction design system • Evaluate usability of resulting instructions Slides from Heiser et al.
Ensure Visibility of Parts • Show parts added in each step • Show mode and location of attachment • Avoid changing viewpoint • Use physically stable orientation Slides from Heiser et al.
Illustrate Assembly Operations • Use action diagrams rather than structural • Use arrows and guidelines to indicate attachment Structural diagrams Action diagrams Slides from Heiser et al.
Improving Aviation Safety with Visualization • Cecilia Aragon, graduated from here • Goal: reduce helicopter landing accidents caused by invisible air turbulence • Approach: use a new technology called lidar and try to visualize its output • Finding: it helped reduce simulated accidents (!) but only when the visualization was made as simple as possible.
Motivation • Invisible airflow hazards cause aircraft accidents • Wind shear • Microbursts • Vortices (turbulence) • Downdrafts • Hot exhaust plumes • Crash of Delta Flight 191 at DFW 1985 (microburst) • NTSB database 1989-99 • 21,380 aircraft accidents • 2,098 turbulence/wind related Slide by Cecilia Aragon
Preliminary Usability Study Slide by Cecilia Aragon
Preliminary usability study: goals • Assess efficacy of presenting airflow data in flight • Obtain expert feedback on presentation of sample hazard indicators to refine design choices Slide by Cecilia Aragon
Usability study: low-fidelity prototype • Rhino3D (3D CAD modeling program) • Easy access to ship models, ease of rapid prototyping • Chosen over 2D paper prototype, MS Flight Simulator, WildTangent, VRML-based tools, Java and Flash • Series of animations simulating helicopter’s final approach to landing • Different types of hazard indicators • Get pilot feedback and suggestions (interactive prototyping) Slide by Cecilia Aragon
Low-fi usability study screen shots Slide by Cecilia Aragon
Low-fi usability study screen shots Slide by Cecilia Aragon
Low-fi usability study participants • Navy helicopter test pilot, 2000 hours of flight time, 17 years experience • Navy helicopter flight test engineer, 2000+ hours of simulator time, 100 hours of flight time, 17 years experience • Civilian helicopter flight instructor, 1740 hours of flight time, 3 years experience Slide by Cecilia Aragon
Low-fi usability study results • All participants said they would use system • Feedback on hazard indicators: • Color: all preferred red/yellow only • Transparency: should be visible enough to get attention, but must be able to see visual cues behind it • Depth cueing: all preferred shadows below object, #1 said shadows alone sufficient. #2 wanted connecting line. No one wanted tick marks or numeric info. • Texture: #1, #2 didn’t want. #3 suggested striping • Shape: Rectilinear and cloud shapes favored. Keep it simple! Watch for conflicting HUD symbology. Slide by Cecilia Aragon
Flight Simulation Usability Study Slide by Cecilia Aragon
Flight Simulation Usability Study • Implement visual hazard display system in simulator based on results from low-fidelity prototype • Advanced Rotorcraft Technology, Inc. in Mountain View, CA, USA • High-fidelity helicopter flight simulator • Accurate aerodynamic models • Use existing ship and helicopter models, flight test data • Simulated hazardous conditions, create scenarios, validated by Navy pilots and flight engineers Slide by Cecilia Aragon
Flight Simulation Usability Study: Participants • 16 helicopter pilots • from all 5 branches of the military (Army, Navy, Air Force, Coast Guard, Marines) • civilian test pilots (NASA) • wide range of experience • 200 to 7,300 helicopter flight hours (median 2,250 hours) • 2 to 46 years of experience (median 13 years) • age 25 to 65 (median age 36) • No previous experience with airflow hazard visualization Slide by Cecilia Aragon
Simulation Experiment Design • 4 x 4 x 2 within-subjects design (each pilot flew the same approaches) • 4 shipboard approach scenarios • 4 landing difficulty levels (US Navy Pilot Rating Scale - PRS 1-4) • Each scenario was flown at all difficulty levels both with and without hazard indicators • Orders of flight were varied to control for learning effects Slide by Cecilia Aragon
Airflow Hazard Indicators in Simulator Slide by Cecilia Aragon
Hypotheses 1. Crash rate will be reduced by the presence of hazard indicator (LD 3). 2. Crashes will be eliminated by red hazard indicator if a standard operating procedure (SOP) is given to the pilots (LD 4). 3. Hazard indicator will not cause distraction or degradation in performance in situations where adequate performance is expected without indicator (LD 2). 4. Pilots will say they would use airflow hazard visualization system Slide by Cecilia Aragon
Hypothesis 1 confirmed Presence of the hazard indicator reduces the frequency of crashes during simulated shipboard helicopter landings (t-test for paired samples, t=2.39, df=63, p=0.00985). 19% --> 6.3% Slide by Cecilia Aragon
Hypothesis 2 confirmed Presence of the red hazard indicator combined with appropriate instructions to the pilot prevents crashes (t=4.39, df=63, p < 0.000022). 23%-->0% Slide by Cecilia Aragon
Hypothesis 3 No negative effect of hazard indicator. 8%-->8% Slide by Cecilia Aragon
Hypothesis 3 (cont’d) Pilots believe hazard indicators were not distracting (Probe 6 results). Slide by Cecilia Aragon
Hypothesis 4 confirmed Pilots would use the system (Probe 21 results). Slide by Cecilia Aragon
Analysis by Pilot Experience Level • Same general trends -- but small sample size • No significant difference between the groups Slide by Cecilia Aragon
Analysis of Subjective Data 94% found hazard indicators helpful Slide by Cecilia Aragon
Analysis of Subjective Data Is motion (animation) helpful or distracting? Slide by Cecilia Aragon
Conclusions • Flight-deck visualization of airflow hazards yields a significant improvement in pilot ability to land safely under turbulent conditions in simulator • Type of visualization to improve operational safety much simpler than that required for analysis • Success of user-centered design procedure Slide by Cecilia Aragon