Information Graphics Jeff McNeill University of Hawaii at Manoa 2007 Copyright © Jeff McNeill, 2007 Licensed under Creative Commons Attribution 3.0 http://creativecommons.org/licenses/by/3.0/

Overview This is an overview of information graphics, good, bad and ugly These can be extremely helpful in walkthrough and summary slides

This is an overview of information graphics, good, bad and ugly

These can be extremely helpful in walkthrough and summary slides

List of Information Graphics 2 x 2 chart Bar chart Concept map Diagram Gannt chart Line chart Map Org chart Parallel coordinates Pert chart Process map Scatter plot Table Tag cloud Venn diagram Meaningful elements Color Size Location Connections (lines) Directionality (arrows) Degree of overlap Proximity Order Label Scale Do not use Radar diagram Parallel coordinates instead Pie chart Bar chart instead

2 x 2 chart

Bar chart

Concept map

Diagram

Gannt chart

Line chart

Map

Org chart

Parallel coordinates

Pert chart

Process map

Scatter plot

Table

Tag cloud

Venn diagram

Meaningful elements

Color

Size

Location

Connections (lines)

Directionality (arrows)

Degree of overlap

Proximity

Order

Label

Scale

Do not use

Radar diagram

Parallel coordinates instead

Pie chart

Bar chart instead

Information Graphics Descriptions * Included in the Notetaking Toolkit. Drawing illustrating parts and relationships Diagram Individual time assignments (project management) Pert chart Usually 2 dimensional plotting, shows clusters Scatter plot 2 dimensions by 2 measurements 2 x 2 chart* 2+ items with overlapping and non- parts Venn diagram* Shows frequency, centrality, importance of terms Tag cloud The basic structured way of comparing items Table* Shows steps in a process, left-to-right with arrows Process map* For 3 or more dimensions, better than radar diagrams or multiple bar or 2 x 2 charts Parallel coordinates Don’t confuse with concept map, only for orgs Org chart Geographical or any 2d space plotting Map Like bar chart but shows slope between datapoints Line chart* (Project management) shows dependencies & time Gannt chart Shows connections and relationships Concept map* One or more measures, can be comparative Bar chart

Graphics Concepts Chartjunk Data-to-ink ratio Colorblindness

Chartjunk

Data-to-ink ratio

Colorblindness

Notetaking Toolkit This toolkit identifies information graphics which are easy to create on the fly when taking notes These should be mastered first and can be useful in gathering information, not just in presenting Includes the 2 x 2 chart, Concept map, Line chart, Process map, Table, and Venn diagram

This toolkit identifies information graphics which are easy to create on the fly when taking notes

These should be mastered first and can be useful in gathering information, not just in presenting

Includes the 2 x 2 chart, Concept map, Line chart, Process map, Table, and Venn diagram

2 x 2 Chart* Simplified version of the Line chart Can be used as a Scatter plot overlay It divides each of two dimensions into two levels, usually low and high Quadrants Most desirable Upper right * Included in the Notetaking Toolkit. low low high high second dimension first dimension

Simplified version of the Line chart

Can be used as a Scatter plot overlay

It divides each of two dimensions into two levels, usually low and high

Quadrants

Most desirable

Upper right

2 x 2 Chart* Components Components Datapoints X and Y Axes X and Y Axes Labels X and Y Axes Level Labels Partition lines into quadrants Datapoint labels (or legend) Variations Datapoints can be scatterplot along interval scales or simply categories low low high high Different Good Good but not different Not good and not different Different but not good Good and different

Components

Datapoints

X and Y Axes

X and Y Axes Labels

X and Y Axes Level Labels

Partition lines into quadrants

Datapoint labels (or legend)

Variations

Datapoints can be scatterplot along interval scales or simply categories

Bar Chart * Included in the Notetaking Toolkit.

Concept Map* Hierarchical composition of elements Visualizes connections between elements (concepts and examples) Can be read to form sentences Superior to “mind mapping” (Buzan) From Novak based on Ausubel Similar to process map, which indicates horizontal, time-ordered relationships Useful for component decomposition * Included in the Notetaking Toolkit.

Hierarchical composition of elements

Visualizes connections between elements (concepts and examples)

Can be read to form sentences

Superior to “mind mapping” (Buzan)

From Novak based on Ausubel

Similar to process map, which indicates horizontal, time-ordered relationships

Useful for component decomposition

Concept Map* Components Elements (circles) Element labels (inside element) Relationships (lines w/ arrows) Relationship labels (optional) Vertical placement Indicates hierarchy Use bottom-up arrows for Goldratt reality trees See also Process map * Included in the Notetaking Toolkit. Food Bean Nut Peanut Almond Examples Includes

Elements (circles)

Element labels (inside element)

Relationships (lines w/ arrows)

Relationship labels (optional)

Vertical placement

Indicates hierarchy

Use bottom-up arrows for Goldratt reality trees

See also Process map

http://www.mc.maricopa.edu/dept/d43/glg/Study_Aids/concept_maps/conceptmaps.html

http://www.mc.maricopa.edu/dept/d43/glg/Study_Aids/concept_maps/conceptmaps.html

Diagram * Included in the Notetaking Toolkit.

Gannt Chart

Line Chart* Similar to the 2 x 2 and chart plots Like bar chart but with slope Usually uses ratio data (interval w/ zero) Can show relationship between two or more variables on different scales * Included in the Notetaking Toolkit. then less now more Choices Time

Similar to the 2 x 2 and chart plots

Like bar chart but with slope

Usually uses ratio data (interval w/ zero)

Can show relationship between two or more variables on different scales

X and Y axes X and Y axes labels One or more lines Data set (optional) Scale indicator labels Scale indicators (optional) Variable labels or legend Projected values (optional) (dotted lines) Line Chart* Components * Included in the Notetaking Toolkit. 2005 0 1,000 Choices Time 500 2006 2007 220 310 570 680 580 400 750 250

X and Y axes

X and Y axes labels

One or more lines

Data set (optional)

Scale indicator labels

Scale indicators (optional)

Variable labels or legend

Projected values (optional) (dotted lines)

Map

Org Chart Typically squares and straight lines Do not use org chart look for non org charts See sociogram (type of concept map) Components include positions and/or persons Hierarchical order Boss and direct reports Support staff off to side President Chris Charlie VP Alice Alfa VP Bob Bravo Assistant Don Delta

Typically squares and straight lines

Do not use org chart look for non org charts

See sociogram (type of concept map)

Components include positions and/or persons

Hierarchical order

Boss and direct reports

Support staff off to side

Parallel Coordinates http://www.nbb.cornell.edu/neurobio/land/PROJECTS/Inselberg/ Parallel Coordinates V L F R High Medium High High Virtual World Low Medium Medium High Online Low Low Low Low Classroom Fantastic Robotic Ludic Virtual

Radar Diagram (Do Not Use) Radar Diagram V L F R Use parallel coordinates instead http://www.internet4classrooms.com/excel_radar.htm High Medium High High Virtual World Low Medium Medium High Online Low Low Low Low Classroom Fantastic Robotic Ludic Virtual

Pert Chart

Process Map* Shows parts and steps Similar to GANTT chart, which shows dependencies and a timeline * Included in the Notetaking Toolkit. Step 1 Step 2 Step 3

Shows parts and steps

Similar to GANTT chart, which shows dependencies and a timeline

Scatter Plot

Table* Extremely flexible and useful Can be used whenever there are two or more things to compare/contrast Columns, rows, headers, and data Primary data collection is row Variables and values are columns Center and align when appropriate Headers usually bold Order of elements Time, importance, alphabetical * Included in the Notetaking Toolkit.

Extremely flexible and useful

Can be used whenever there are two or more things to compare/contrast

Columns, rows, headers, and data

Primary data collection is row

Variables and values are columns

Center and align when appropriate

Headers usually bold

Order of elements

Time, importance, alphabetical

Table* Examples Data collection units are ususally rows Totals go down rows (vs. across columns) Any information can be placed in tables Increases speed and accuracy of understanding and visual comparisons * Included in the Notetaking Toolkit. Incorrect Correct Sold Weight Cost 2,000 1,000 50 lbs 100 lbs $2.00 $1.00 Ver 2 Ver 1 3,000 2,000 1,000 Sold Total 50 lbs 100 lbs Weight Ver 2 Ver 1 Version $5,000 $4,000 $2.00 $1,000 $1.00 Sales Cost

Data collection units are ususally rows

Totals go down rows (vs. across columns)

Any information can be placed in tables

Increases speed and accuracy of understanding and visual comparisons

Tag (Text) Cloud Alphabetical or some other meaningful arrangement Meaningful dimensions Size = frequency Color = time (or other), optional Proximity = similarity Advanced versions become similar to multidimensional cluster plots

Alphabetical or some other meaningful arrangement

Meaningful dimensions

Size = frequency

Color = time (or other), optional

Proximity = similarity

Advanced versions become similar to multidimensional cluster plots

Tag (Text) Cloud Steve Jobs 2007 Macworld Conference Avg. Words/Sentence: 10.5 Lexical Density : 16.5% Hard Words : 2.9% Gunning Fog Index : 5.5 Bill Gates 2007 Consumer Electronics Show Avg. Words/Sentence: 21.6 Lexical Density : 21.0% Hard Words : 5.11% Gunning Fog Index : 10.7

Indicates commonality and difference Overlaps share or combine qualities Venn Diagram* Ice Cream Cake Chocolate Chocolate Ice Cream Cake

Indicates commonality and difference

Overlaps share or combine qualities

Additional Notes

Information Visualization CMSC 838B – Spring 2003 Visual Design Benjamin B. Bederson University of Maryland www.cs.umd.edu/~bederson This presentation adapted from John Stasko

Semiotics The study of symbols and how they convey meaning Classic book: J. Bertin, 1983, The Semiology of Graphics This presentation taken largely from John Stasko

The study of symbols and how they convey meaning

Classic book:

J. Bertin, 1983, The Semiology of Graphics

Related Disciplines Psychophysics Applying methods of physics to measuring human perceptual systems How fast must light flicker until we perceive it as constant? What change in brightness can we perceive? Cognitive psychology Understanding how people think, here, how it relates to perception

Psychophysics

Applying methods of physics to measuring human perceptual systems

How fast must light flicker until we perceive it as constant?

What change in brightness can we perceive?

Cognitive psychology

Understanding how people think, here, how it relates to perception

Potential Preattentive Features length width size curvature number terminators intersection closure hue intensity flicker direction of motion binocular lustre stereoscopic depth 3-D depth cues lighting direction

Key Perceptual Properties Brightness Color Texture Shape

Brightness

Color

Texture

Shape

Luminance/Brightness Luminance Measured amount of light coming from some place Brightness Perceived amount of light coming from source

Luminance

Measured amount of light coming from some place

Brightness

Perceived amount of light coming from source

Color for Categories Can different colors be used for categories of nominal variables? Yes Ware’s suggestion: 12 colors red, green, yellow, blue, black, white, pink, cyan, gray, orange, brown, purple

Can different colors be used for categories of nominal variables?

Yes

Ware’s suggestion: 12 colors

red, green, yellow, blue, black, white, pink, cyan, gray, orange, brown, purple

Color Categories Are there certain canonical colors? Post & Greene ‘86 had people name different colors on a monitor Pictured are ones with > 75% commonality

Are there certain canonical colors?

Post & Greene ‘86 had people name different colors on a monitor

Pictured are ones with > 75% commonality

Color for Sequences Can you order these (low->hi)

Possible Color Sequences Gray scale Single sequence part spectral scale Full spectral scale Single sequence single hue scale Double-ended multiple hue scale

Color Purposes Call attention to specific data Increase appeal, memorability Increase number of dimensions for encoding data Example, Ware and Beatty ‘88 x,y - variables 1 & 2 amount of r,g,b - variables 3, 4, & 5

Call attention to specific data

Increase appeal, memorability

Increase number of dimensions for encoding data

Example, Ware and Beatty ‘88

x,y - variables 1 & 2

amount of r,g,b - variables 3, 4, & 5

1. Graph Graph - Show the relationships between variables’ values in a data table Visual display that illustrates one or more relationships among entities Shorthand way to present information Allows a trend, pattern or comparison to be easily comprehended

Graph - Show the relationships between variables’ values in a data table

Visual display that illustrates one or more relationships among entities

Shorthand way to present information

Allows a trend, pattern or comparison to be easily comprehended

Issues Critical to remain task-centric Why do you need a graph? What questions are being answered? What data is needed to answer those questions? Who is the audience? time money

Critical to remain task-centric

Why do you need a graph?

What questions are being answered?

What data is needed to answer those questions?

Who is the audience?

Graph Components Framework Measurement types, scale Content Marks, lines, points Labels Title, axes, ticks

Framework

Measurement types, scale

Content

Marks, lines, points

Labels

Title, axes, ticks

Basic Data Types Nominal (qualitative) (no inherent order) city names, types of diseases, ... Ordinal (qualitative) (ordered, but not at measurable intervals) first, second, third, … cold, warm, hot Interval (quantitative) list of numbers

Nominal (qualitative)

(no inherent order)

city names, types of diseases, ...

Ordinal (qualitative)

(ordered, but not at measurable intervals)

first, second, third, …

cold, warm, hot

Interval (quantitative)

list of numbers

Common Graph Formats Line graph Bar graph Scatter plot Y-axis is quantitative variable See changes over consecutive values Y-axis is quantitative variable Compare relative point values Two variables, want to see relationship Is there a linear, curved or random pattern?

Graphing Guidelines Independent vs. dependent variables Put independent on x-axis See resultant dependent variables along y-axis If there are two independent variables, often place them along the 2 axes (you choose which) and then the mark may encode the dependent variable

Independent vs. dependent variables

Put independent on x-axis

See resultant dependent variables along y-axis

If there are two independent variables, often place them along the 2 axes (you choose which) and then the mark may encode the dependent variable

2. Chart Structure is important, relates entities to each other Primarily uses lines, enclosure, position to link entities Examples: flowchart, family tree, org chart, ...

Structure is important, relates entities to each other

Primarily uses lines, enclosure, position to link entities

3. Map Representation of spatial relations Locations identified by labels

Representation of spatial relations

Locations identified by labels

Choropleth Map Areas are filled and colored differently to indicate some attribute of that region

Cartography Cartographers and map-makers have a wealth of knowledge about the design and creation of visual information artifacts Labeling, color, layout, … Information visualization researchers should learn from this older, existing area

Cartographers and map-makers have a wealth of knowledge about the design and creation of visual information artifacts

Labeling, color, layout, …

Information visualization researchers should learn from this older, existing area

4. Diagram Schematic picture of object or entity Parts are symbolic Examples: figures, steps in a manual, illustrations,...

Schematic picture of object or entity

Parts are symbolic

Tufte’s Design Principles 1. Tell the truth Graphical integrity 2. Do it effectively with clarity, precision… Design aesthetics E. Tufte , The Visual Display of Quantitative Information (1983) E. Tufte , Envisioning Information (1990) E. Tufte , Visual Explanations (1997)

1. Tell the truth

Graphical integrity

2. Do it effectively with clarity, precision…

Design aesthetics

1. Graphical Integrity 2002 2001 2000 1999 1998 500 475 450 Stock market crash? Your graphic should tell the truth about your data

Your graphic should tell the truth about your data

Show entire scale 2002 2001 2000 1999 1998 500 250 0

Show in context 2000 1990 1980 1970 1960 500 250 0

Measuring Misrepresentation Visual attribute value should be directly proportional to data attribute value Height/width vs. area vs. volume Size of effect shown in graphic Size of effect in data Lie factor = “ Lie factor” = 2.8

Visual attribute value should be directly proportional to data attribute value

Height/width vs. area vs. volume

2. Design Principles Maximize data-ink ratio Data ink ratio = Data ink Total ink used in graphic = proportion of graphic’s ink devoted to the non-redundant display of data-information

Maximize data-ink ratio

Design Principles Avoid chartjunk Extraneous visual elements that detract from message don’t be the duck of architecture

Avoid chartjunk

Extraneous visual elements that detract from message

Design Principles Utilize multifunctioning graphical elements Graphical elements that convey data information and a design function

Utilize multifunctioning graphical elements

Graphical elements that convey data information and a design function

Design Principles Use small multiples Repeat visually similar graphical elements nearby rather than spreading far apart

Use small multiples

Repeat visually similar graphical elements nearby rather than spreading far apart

Design Principles Show mechanism, process, dynamics, and causality Cause and effect are key

Show mechanism, process, dynamics, and causality

Cause and effect are key

Design Principles Escape flatland Data is multivariate Doesn’t necessarily mean 3D projection

Escape flatland

Data is multivariate

Doesn’t necessarily mean 3D projection

Design Principles Utilize layering and separation

Utilize layering and separation

Design Principles Utilize narratives of space and time Tell a story of position and chronology through visual elements

Utilize narratives of space and time

Tell a story of position and chronology through visual elements

Design Principles Content is king Quality, relevance and integrity of the content is fundamental What’s the analysis task? Make the visual design reflect that Integrate text, chart, graphic, map into a coherent narrative

Content is king

Quality, relevance and integrity of the content is fundamental

What’s the analysis task? Make the visual design reflect that

Integrate text, chart, graphic, map into a coherent narrative

Graph and Chart Tips Avoid separate legends and keys – Put that in the graphic Make grids & labeling faint so that they recede into background

Avoid separate legends and keys – Put that in the graphic

Make grids & labeling faint so that they recede into background

Proper Color Use To label To measure To represent or imitate reality To enliven or decorate

To label

To measure

To represent or imitate reality

To enliven or decorate

Color Examples

Guides for Enhancing Visual Quality Attractive displays of statistical info have a properly chosen format and design use words, numbers and drawing together reflect a balance, a proportion, a sense of relevant scale display an accessible complexity of detail often have a narrative quality, a story to tell about the data are drawn in a professional manner, with the technical details of production done with care avoid content-free decoration, including chartjunk

Attractive displays of statistical info

have a properly chosen format and design

use words, numbers and drawing together

reflect a balance, a proportion, a sense of relevant scale

display an accessible complexity of detail

often have a narrative quality, a story to tell about the data

are drawn in a professional manner, with the technical details of production done with care

avoid content-free decoration, including chartjunk

Graphical Displays Should Show the data Induce the viewer to think about substance rather than about methodology, graphic design the technology of graphic production, or something else Avoid distorting what the data have to say Present many numbers in a small space Make large data sets coherent Encourage the eye to compare different pieces of data Reveal the data at several levels of detail, from a broad overview to the fine structure Serve a reasonably clear purpose: description, exploration, tabulation, or decoration Be closely integrated with statistical and verbal descriptions of a data set

Show the data

Induce the viewer to think about substance rather than about methodology, graphic design the technology of graphic production, or something else

Avoid distorting what the data have to say

Present many numbers in a small space

Make large data sets coherent

Encourage the eye to compare different pieces of data

Reveal the data at several levels of detail, from a broad overview to the fine structure

Serve a reasonably clear purpose: description, exploration, tabulation, or decoration

Be closely integrated with statistical and verbal descriptions of a data set