cs5984: Information Visualization Chris North 2-D cs5984: Information Visualization Chris North

2-D Image browsing Maps

Today Bederson, “Pad++”, p 530 Furnas, “Space-Scale Diagrams”, web dilshad, satya Furnas, “Space-Scale Diagrams”, web

Space-Scale

Pad++ on edge Like ray-tracing Info surface zoom window

Semantic Zooming Zooming in, red object turns to blue

Multiple Views Zoom factor ~ 20

Multiple levels = large scale Zoom factor = 20 * 20 * 20 = 8000

Multiple Foci

Multiple Overviews Can have different information types at each level

2-D + Attributes Dynamaps: dynamic queries on maps

Assignment Read for Tues (2-D: Focus+Context) Robertson, “Document Lens”, p 562 ashwini, aejaaz Spence, “Bifocal Lens”, p 331,333 Read for Thurs (Visual Overview Strategies) Stasko, “Information Mural”, web sanjini, luhui Project Proposal due Tues!

Evaluation Principled, algorithmic Usability Empirical user studies ** Compare multiple visualizations Independent variables: Visualization, User task, Data size, … Dependent variables: 5 HCI metrics

e.g. 2 x 3 design n users per cell Statistics to test for “significant” difference: t-tests, anova Ind.Var 2 Task1 Task2 Task3 Home-finder Form fill-in Measured user performance times (dep. Var) Ind.Var 1