Information Visualization Chris North cs3724: HCI

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

The Big Problem Data Human How? Data Transfer contacts, dict/thes, music, news, , web Books, papers, scientific data, VB ref vision: 90Mb/sec Hear: 10/s, 44k/s Smell: 1 Touch: Taste Neural link: huge esp

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: The pop-out effect

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

Per Capita Income College Degree %

Visual Representation Matters! Text vs. Graphics What if you could only see 1 state’s data at a time? (e.g. Census Bureau’s website) What if I read the data to you?

The Big Problem Data Human How? Data Transfer

Information Integration

The Bigger Problem Data Human How? Data Transfer

Interactive Graphics Homefinder

forms Avoid the temptation to design a form-based search engine More tasks than just “search” How do I know what to “search” for? What if there’s something better that I don’t know to search for? Hides the data

User Tasks Easy stuff: Min, max, average, % These only involve 1 data item or value 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!

More than just “data transfer” Glean higher level knowledge from the data Reveals data Reveals information about data that is not necessarily “stored” in the data Learn = data  information Insight! Hides data Hides “information” Nothing learned Zero insight

More than just “data transfer” Glean higher level knowledge from the data Reveals data Reveals information about data that is not necessarily “stored” in the data Learn = data  information Insight! Hides data Hides “information” Nothing learned Zero insight The Insight Factor

Class Motto Show me the data!

What’s the Big Deal?

Presentation is everything!

My Philosophy: Optimization Visualization = the best of both Impressive computation + impressive cognition Computer Serial Symbolic Static Deterministic Exact Binary, 0/1 Computation Programmed Follow instructions Amoral Human Parallel Visual Dynamic Non-deterministic Fuzzy Gestalt, whole, patterns Understanding Free will Creative Moral

Visualization Design Principles

Increase Data Density Calculate data/pixel “A pixel is a terrible thing to waste.”

Eliminate “Chart Junk” How much “ink” is used for non-data? Reclaim empty space (% screen empty) Attempt simplicity (e.g. am I using 3d just for coolness?)

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

InfoVis Design Principles Increase data density Eliminate “chart junk” Mantra: Overview first, zoom&filter, details on demand Insight factor Does the design reveal the data? Does the design help me explore, learn, understand? Show me the data!