Information Design and Visualization Chris North CS 3724: HCI

To do Hall of Fame/Shame Presentations Project: Requirements Analysis

Information scenarios ANALYZE analysis of stakeholders, field studies claims about current practice Problem scenarios DESIGN Activity scenarios metaphors, information technology, HCI theory, guidelines Functionality iterative analysis of usability claims and re-design Information scenarios Look and feel Interaction scenarios PROTOTYPE & EVALUATE summative evaluation formative evaluation Usability specifications

The Problem Data Human Data Transfer Goal: Insight How?

Human Vision Highest bandwidth sense Fast, parallel Pattern recognition Pre-attentive Extends memory and cognitive capacity (Multiplication test) People think visually Impressive. Lets use it!

Find the Red Square:

Which state has highest Income? Relationship between Income and Education? Outliers?

College Degree % Per Capita Income

Scenarios = Data + Tasks Data categories: Spatial (1,2,3D) Tabular (Multi-dimensional) Network, Tree Text, documents Combinations of categories

Visualization can do this! User Tasks Easy stuff: (1 or few items) Min, max, average, % Exact queries, known item search Hard stuff: Patterns, trends, distributions, changes over time, outliers, exceptions, relationships, correlations, multi-way, combined min/max, tradeoffs, clusters, groups, comparisons, context, anomalies, data errors, Paths, … Excel can do this Visualization can do this!

Examples of Tabular data visualization DataMaps Spotfire TableLens

DataMaps demo

Spotfire Mapping data to graphics (x, y, size, color, shape…) Multiple views: brushing and linking Dynamic Queries Details window Cars data

Visual Mapping: Step 1 Map: data items  visual marks Visual marks: Points Lines Areas Volumes Glyphs

Visual Mapping: Step 2 Map: data items  visual marks Map: data attributes  visual properties of marks Visual properties of marks: Position, x, y, z Size, length, area, volume Orientation, angle, slope Color, gray scale, texture Shape Animation, time, blink, motion

Mapping Example in Spotfire Film database Film  dot Year  x Length  y Popularity  size Subject  color Award?  shape

TableLens (Eureka by Inxight) Visual encoding of cell values Details expand within context (fisheye) Sorting Cars data

Examples of Tree data visualization Windows Explorer Star Tree TreeMaps

Star Tree (Hyperbolic Tree) Focus+Context Radial; shrink with distance to center Drag to navigate Scalability? Xerox PARC, Inxight http://startree.inxight.com/

Treemaps Parent/child containment Size & color encoding Map of the Market: http://www.smartmoney.com/marketmap/ People Map: http://www.truepeers.com/ Coffee Map: http://www.peets.com/tast/11/coffee_selector.asp U. Maryland

“Squarified” TreeMap http://www.research.microsoft.com/~masmith/all_map.jpg

SequoiaView http://www.win.tue.nl/sequoiaview/

Context is Important!

Information Visualization Mantra Overview first, zoom and filter, then details on demand - Ben Shneiderman

What is Information Visualization? The use of computer-supported, interactive, visual representations of abstract data to amplify cognition

My definition: Show me the data!

Keys points Power of visual system scenario = data + tasks Mapping data to graphics & visual properties 2 steps Interaction for what doesn’t fit in visual rep. Dynamic queries, brushing, … Examples: tabular data, trees Mantra: Overview first… Choice of visual representation matters

What’s the Big Deal?

Presentation is everything! - Edward Tufte Presentation is everything!

Project Step 3 – Design Due 3 weeks: get started early! Design space Dimensions of the design space Alternative designs Claims analysis Formative evaluation Wizard of Oz Refinements Final design: Scenarios Representations

Homework #3 Due next Thurs Download KidPad software Design a zoomable visualization