Comp 15 - Usability & Human Factors Unit 12b - Information Visualization This material was developed by Columbia University, funded by the Department of Health and Human Services, Office of the National Coordinator for Health Information Technology under Award Number 1U24OC

Hypervariate data sets Implementation: scaling (in space or time) Scaling in space: use different portion of the screen to show overview of the whole data set and detail of the selected subset Scaling in time: alternate between overview of the whole set and detail of the selected subset sequentially in the same space Solution: overview of the whole set and details of the selected subset Common problem: many data sets are too large to visualize on one screen Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Scaling Variation in space Can overview and detail co-exist in the same space? Distortion Fish-eye view Bifocal display Perspective wall Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Scaling Fish-Eye George Furnas 1981 Shneiderman: Provide[s] detailed view (focus) and overview (context) without obscuring anything… The focus area (or areas) is magnified to show detail, while preserving the context, all in the single display. Fish- eye view Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring D Fisheye 2D Fisheye

Scaling Fish-Eye (cont.) Fish-eye view Examples: Fish-eye views for long menusBederson UIST’00http:// Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Fish-eye views Examples: Fish-eye views for graphs Scaling Fish-Eye (cont.) Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Scaling Bifocal Bifocal display First suggested by Spence and Apperley (1980) Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Scaling Bifocal (cont.) Bifocal display Examples Early implementationSpence – 1980? spence/videos.htm Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Scaling Perspective Wall Perspective Wall Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring Perspective wallBifocal display

Scaling Perspective Wall (cont.) Perspective Wall Examples: Map work charts onto diagram x-axis is time, y-axis is project (Mackinlay, Robertson, Card ’91) Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Scaling Perspective Wall (cont.) Perspective wall Examples: File navigation /cpsc533c-03- spr/0127.quanzhe ngeng.ppthttp:// /cpsc533c-03- spr/0127.quanzhe ngeng.ppt Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Time Scaling Magic Lens Panning and Zooming Variation in time Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Magic Lens Scaling Magic Lens com/istl/projects/ MagicLenses/Sim pleDemo.html Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Panning & Zooming Scaling Panning and Zooming Panning – smooth movement of camera across scene (or scene moves and camera stays still) Zooming – increasing or decreasing the magnification of the objects in a scene 0.5/jazz-mid-talk.htmlhttp:// 0.5/jazz-mid-talk.html Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Hierarchies and Trees Definition Data repository in which cases are related to subcases Hierarchies in the world Family histories File/directory Organizational chart Object-oriented software classes Main representation Node-link Space-filling Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Node-link Hierarchies Root at top Image source: “Data structures and file handling: Tree-Maps: a space-filling approach to the visualization of hierarchical information structures”, Brian Johnson, Ben Shneiderman Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Node-link Hierarchies ExamplesProblems Quickly fills out screen real estate Difficult to maintain overview of the structure Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Node-link Hierarchies Potential solutions Cone Trees (PARC, Robertson, Mackinlay, Card) Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Space-filling Treemap examples Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Time Series Data Definition Data sets with one variable being the time of the event Could be uni- or hypervariable Data mining – looking for patters Visualization – looking for visual patterns Standard presentation Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Time Series Data (con’t) Predictive calendars Examples Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Time Series Data (con’t) One issue – temporal data is often periodic (cycles – daily, weekly, yearly, etc.) Linear display is problematic for periodic data Potential answer – spiral display Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Additional benefit of spiral display – discovering periodicity in data Time Series Data (con’t) Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Interaction and Dynamic Queries Data transformation Details on demand Dynamic query Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Interaction and Dynamic Queries (con’t) Data transformation Details on demand Details could be removed from the main view for different reasons (mainly due to scaling issues) Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Interaction and Dynamic Queries (con’t) Data transformation Dynamic queries Visual representation of all possible objects and actions Rapid, incremental and reversible actions Direct manipulation is favored (selection by pointing, not typing) Specifying a query brings immediate display of results Responsive interaction (< 0.1 sec) Classic example: HomeFinder – 1992, University of Maryland, Human Computer Interaction Lab (Ben Shneiderman) Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Information Visualization in Medicine Purpose : Visually present medical data in more intuitive, easy to understand, learn, recognize, navigate and manage formats Visually magnify subtle aspects of the diagnostic, therapeutic, patient management and healing process which otherwise could be difficult to notice Prevent information overload and allow members of clinical staff to master large quantities of information Luca Chittaro, “Information Visualization and its Application to Medicine” Artificial Intelligence in Medicine, vol.22(2), 2001, pp Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Information Visualization in Medicine (con’t) Examples The Visible Human Explorer ( hcil/visible- human/vhe.shtml) hcil/visible- human/vhe.shtml Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Information Visualization in Medicine (con’t) Examples Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Information Visualization in Medicine (con’t) Examples Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Information Visualization in Medicine (con’t) Examples Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring

Conclusions Assignments Component 15/Unit 12b Health IT Workforce Curriculum Version 2.0/Spring