Information Visualization Crash Course
Chad Stolper, Georgia Tech
chadstolper@gatech.edu
1(AKA Information Visualization 101)
Information Visualization Crash Course (AKA Information - - PowerPoint PPT Presentation
Information Visualization Crash Course (AKA Information Visualization 101) Chad Stolper, Georgia Tech chadstolper@gatech.edu 1 5 th Year Computer Science PhD Student 2 John Stasko, Interactive Computing Polo Chau, Computational Science and
Information Visualization Crash Course
Chad Stolper, Georgia Tech
chadstolper@gatech.edu
1(AKA Information Visualization 101)
5th Year Computer Science PhD Student
2John Stasko, Interactive Computing Polo Chau, Computational Science and Engineering
3What is Infovis? Why is it Important? Human Perception Chart Basics
(If Time, Some Color Theory)
The Shneiderman Mantra Where to Learn More
9Questions Encouraged!
10Questions Encouraged!
11What is Information Visualization?
12Information Visualization
“The use of computer-supported, interactive, visual representations of abstract data to amplify cognition.” Card, Mackinlay, and Shneiderman 1999
13Communication Exploratory Data Analysis
14Communication
15Communication Gone Wrong
16Space Shuttle Challenger
January 28, 1986
18Morning Temperature: 31°F
19What happened?
20https://www.youtube.com/watch?v=6Rwcbsn19c0
How did this happen?
24Morton Thiokol’s Presentation
25On the other hand…
40Exploratory Data Analysis
42“There are three kinds of lies: lies, damned lies, and statistics.”
43Mystery Data Set
44Mystery Data Set
Property Value mean( x ) 9 variance ( x ) 11 mean( y ) 7.5 variance ( y ) 4.122 correlation ( x,y ) 0.816 Linear Regression Line y = 3 + 0.5x
45Anscombe’s Quartet
51https://en.wikipedia.org/wiki/Anscombe%27s_quartet
Anscombe’s Quartet Sanity Checking Models Outlier Detection
52Anscombe’s Quartet Sanity Checking Models Outlier Detection
53Anscombe’s Quartet Sanity Checking Models Outlier Detection
54Anscombe’s Quartet Sanity Checking Models Outlier Detection
55Human Perception
57Name the five senses.
59Sense Bandwidth (bits/sec) Sight 10,000,000 Touch 1,000,000 Hearing 100,000 Smell 100,000 Taste 1,000
http://www.britannica.com/EBchecked/topic/287907/information-theory/214958/PhysiologyA (Simple) Model
A (Simple) Model of Human Perception
Parallel detection of basic features into an iconic store Serial processing of
identification and spatial layout
Stage 1 Stage 2
62Stage 1: Pre-Attentive Processing
Rapid Parallel Automatic (Fleeting)
63Stage 2: Serial Processing Relatively Slow (Incorporates Memory) Manual
64Stage 1: Pre-Attentive Processing
The eye moves every 200ms
65Stage 1: Pre-Attentive Processing
The eye moves every 200ms (so this processing occurs every 200ms-250ms)
66Example
1281768756138976546984506985604982826762 9809858458224509856458945098450980943585 9091030209905959595772564675050678904567 8845789809821677654876364908560912949686
67Example
1281768756138976546984506985604982826762 9809858458224509856458945098450980943585 9091030209905959595772564675050678904567 8845789809821677654876364908560912949686
68A few more examples from
Left Side Right Side
Raise your hand if a RED DOT is present…
71Color (hue) is pre-attentively processed.
74Raise your hand if a RED DOT is present…
75Shape is pre-attentively processed.
78Determine if a RED DOT is present…
79Hue and shape together are NOT pre-attentively processed.
82Pre-Attentive Processing
motion
lustre
depth
cues
direction
83Stephen Few “Now You See It”
Pre-Attentive à Cognitive
85Gestalt Psychology
Berlin, Early 1900s
86Gestalt Psychology
Goal was to understand pattern perception
Gestalt (German) = “seeing the whole picture all at once”
Identified 8 “Laws of Grouping”
87http://study.com/academy/lesson/gestalt-psychology-definition-principles-quiz.html
Gestalt Psychology
How many groups are there?
89Proximity
91How many groups are there?
92Similarity
94How many shapes are there?
95Closure
97How many items are there?
98[ ] { } [ ]
99Symmetry
[ ] { } [ ]
100How many sets are there?
101Common Fate
How many objects are there?
104Continuity
106How many objects are there?
107Good Gestalt
109What is this word? (Please Shout)
110Past Experience
Past Experience
Pre-Attentive Processing Gestalt Laws
114Detect Quickly
115Detect Quickly
Detect Accurately
116Positions Rectangular areas
(aligned or in a treemap)
Angles Circular areas
Crowdsourced Results
1.0 1.5 2.0 2.5 3.0 T1 T2 T3 T4 T5 T6 T7 T8 T9Log Error
Positions Rectangular areas (aligned or in a treemap) Angles Circular areasMore accurate Less accurate
I I
PositionIMll
1 I
LengthF-l
Iha I
I0.I
I I
Volumerl
l¶kJ ColorAn example analysis for area perception is shown in Figure 16. The top line shows that a series of decreasing areas can be used to encode a tenfold quantitative
randomly, making it more difficult to judge the relative sizes of different areas accurately (hence, area is ranked fifth in Figure 14). Nevertheless, small mis- judgments about the size of an area only leads to small misperceptions about the corresponding quantitative value that is encoded. The middle line shows that area can encode three ordinal values. However, one must be careful to make sure
ACM TransactionsMackinlay, 1986
119Stephen Few “Now You See It”
What does this tell us?
121Barcharts, scatterplots, and line charts are really effective for quantitative data
20 40 20 40 20 40 20 40 20 40
1225 10 15 20 25
1235 10 15 20 25 30 5 10 15 20 25
1245 10 15 20 25 30 5 10 15 20 25
125(and for statistical distributions) Tukey Box Plots
126Median Outliers Largest < Q3 + 1.5 IQR Smallest > Q1 - 1.5 IQR Largest < Q3 Smallest > Q1
127Tufte’s Chart Principles
129Edward Tufte
Edward Tufte
Tufte’s Chart Principles
DO NOT LIE!
Maximize Data-Ink Ratio Minimize Chart Junk
132Tufte’s Chart Principles
DO NOT LIE!
Maximize Data-Ink Ratio Minimize Chart Junk
133http://www.perceptualedge.com/blog/?p=790
13610 20 30 10 20 30 10 20 30 10 20 30 10 20 30
138Tufte’s Chart Principles
DO NOT LIE!
Maximize Data-Ink Ratio Minimize Chart Junk
13910 20 30 10 20 30 10 20 30 10 20 30 10 20 30
141Please…
142No pie charts. No 2.5D charts.
14337 36 24 2 1
1455 10 15 20 25 30 35 40
146PLEASE DON’T EVER DO THIS!
14810 20 30 40
149Two times to use a pie chart…
15050-50
15175-25
152But otherwise…
153Barcharts, scatterplots, and line charts are really effective for quantitative data
20 40 20 40 20 40 20 40 20 40
154Anyone else bored by my color choices?
155In fact, grayscale can be risky…
156In fact, grayscale can be risky…
157Color is Powerful
158Call attention to information Increase appeal Increase memorability Another dimension to work with
Color
159How many of you have heard of RGB?
160We see in RGB, but we don’t interpret in RGB…
162How many have heard of HSV?
163HSV Color Model
Hue/“Color” Saturation/Chroma Value/Lightness
164Hue
Post & Greene, 1986
166Hue
http://blog.xkcd.com/2010/05/03/color-survey-results/ 167Hue and Culture
http://www.informationisbeautiful.net/visualizations/colours-in-cultures/
168Hue and Colorblindness
10% of males and 1% of females are Red-Green Colorblind
169May be better to consider a third model:
Hue – Saturation - LUMINANCE
171Saturation Luminance values Hue
Corners of the RGB color cube L from HLS All the same Luminance values
Luminance
Hello, here is some text. Can you read what it says? Hello, here is some text. Can you read what it says? Hello, here is some text. Can you read what it says? Hello, here is some text. Can you read what it says? Hello, here is some text. Can you read what it says? Hello, here is some text. Can you read what it says? Hello, here is some text. Can you read what it says?
174Color and Quantitative Data
Gray scale Single sequence part spectral scale Full spectral scale Single sequence single hue scale Double-ended multiple hue scale 176Color and Quantitative Data
Can you order these (lowàhi)?
177us
Binary Diverging Categorical Sequential Categorical Categorical
http://www.personal.psu.edu/faculty/c/a/cab38/ColorSch/Schemes.htmlvia MunznerColor Scales
Color Brewer
http://colorbrewer2.org/
179Overview Zoom+Filter Details on Demand
Shneiderman Mantra (Information-Seeking Mantra)
180http://visual.ly/every-single-death-game-thrones-series
182and finally…
188William Playfair, 1786
189John Snow, 1854
Charles Minard, 1869
191Where to learn more?
192CS 7450 Information Visualization Every Fall
193How to Make Good Charts
– http://www.edwardtufte.com/tufte/courses
Information
– http://www.edwardtufte.com/tufte/books_vdqi
Designing Tables and Graphs to Enlighten
– http://www.amazon.com/Show-Me-Numbers- Designing- Enlighten/dp/0970601972/ref=la_B001H6IQ5M_1_ 2?s=books&ie=UTF8&qid=1385050724&sr=1-2
194Visualization Theory “Books”
– http://www.cs.ubc.ca/~tmm/talks.html – http://www.cs.ubc.ca/~tmm/vadbook/
– http://www.amazon.com/Information-Visualization-Perception-Interactive- Technologies/dp/1558605118
– http://www.amazon.com/Now-You-See-Visualization- Quantitative/dp/0970601980/ref=pd_bxgy_b_img_z
– http://www.edwardtufte.com/tufte/books_ei
– http://www.edwardtufte.com/tufte/books_visex
– http://www.edwardtufte.com/tufte/books_be
– http://www.amazon.com/Visualization-Analysis-Design-AK- Peters/dp/1466508914
195Perception and Color Websites
– http://www.csc.ncsu.edu/faculty/healey/PP/index.h tml
– http://colorbrewer2.org/
Workshops)
– http://www.stonesc.com/color/index.htm
NASA
– http://blog.visual.ly/subtleties-of-color/
196Visualization Blogs
– http://flowingdata.com/
– http://infosthetics.com/
– http://www.informationisbeautiful.net/
– http://blog.visual.ly/
– http://thisisindexed.com/
197Infographics
Visual.ly/view
(wtfviz.net)
198Visualization @GeorgiaTech
vis.gatech.edu
(less under construction than before... but still under construction)
199Thanks!
Chad Stolper
chadstolper@gatech.edu
200Questions?
Chad Stolper
chadstolper@gatech.edu
201 thisisindexed.com Jessica Hagy