Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
1
Show Me the NumbersCommunicating Effectively with Charts
Stephen Few
In 1786, an iconoclastic Scot William Playfair published a small atlas that introduced or greatly improved most of the quantitative graphs that we use today.
Prior to this, graphs of quantitative data were little known.
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
2
Today, 220 years later, partly due to the arrival of the PC, graphs are commonplace, fully integrated into the fabric of modern communications.
Surprisingly, however, Playfairs innovative efforts sprung from meager precedent are still superior to most of the graphs produced today.
A powerful language,with such promise,
is largely being wasted!
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
3
Despite a recent explosion in available data, most lies stagnant in ever-expanding pools.
Data is useless until we understand what it means and can clearly communicate that meaning to those who need it, those whose decisions affect our world.
Sohere you are today.
You have a choice.
You can demand better.
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
4
Finally
Effective network monitoring has arrived!
Near real-time
Phenomenally user-friendly
Instant insight effective response
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
5
Just show me the numbers!
We are awash in data.
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
6
Why? Numbers are critical to business.
Right?
Were getting better at handling numbers
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
7
Are you sure it isnt in here?
Do you know where your Business Intelligence (BI) investment is now?
Quantitative information is primarily communicated through tables and graphs.
But few communicate effectively. Why?
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
8
Intentional deceit is no longer our biggest problem
Numbers need never be vague or ambiguous
3+2=??!!#!!!&%***@!
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
9
What happened?
The PC happened!
Numbers are commonly obscured, then made to look .
Example #1 - Poor
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
10
Example #1 - Good
Example #2 - Poor
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
11
Example #2 - Good
Example #3 - Poor
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
12
Example #3 - Worse
Example #3 - Good
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
13
Example #4 - Poor
Example #4 - Good
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
14
Warning!
Even software vendors encourage poor design
Example: Totals of something or other by year
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
15
Example: Percentage revenue per product line
Example: Revenue by service line
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
16
Example: Purchases by product line and buyer
Example: Profit by part and month
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
17
Example: Revenue by sales channel and quarter
Example: Revenue by product and quarter
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
18
Example: Expenses by GL account category and account
Example: Hotel revenue by service and quarter
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
19
Example: Revenue vs. costs per month
Example: Your guess is as good as mine
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
20
Do the vendors poor examples matter?
Contest Scenario:This scenario involves the display of departmental salary expenses. It is used by the VP of Human Resources to compare the salary expenses of the companys eight departments as they fluctuate through time, in total and divided between exempt and non-exempt employees.
Time-Series Solution #1
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
21
Time-Series Solution #2
Time-Series Solution #3
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
22
Time-Series Solution #4
Time-Series Solution One that works
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
23
What do tables and graphs help us do?
Above all else show the data.Edward Tufte
Thinkand
Communicate
Communication problems whether verbal or visual are basically the same
I returned, and saw under the sun, that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favor to men of skill; but time and chance happen to them all.
Ecclesiastes 9:11 (King James version of the Bible)
Objective consideration of contemporary phenomena compels the conclusion that success or failure in competitive activities exhibits no tendency to be commensurate with innate capacity, but that a considerable element of the unpredictable must invariably be taken into account.
George Orwells rewrite of this passage into bloated prose
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
24
The two fundamental challenges of data presentation
1. Determining the medium that tells the story best
2. Designing the visual components to tell the story clearly
0
10
20
30
40
50
60
70
80
90
1st Qtr 2nd Qtr 3rd Qtr 4th Qtr
East
West
North
From
toRevenue
0
20
40
60
80
100
1st Qtr 2nd Qtr 3rd Qtr 4th Qtr
Year 2003
U.S.$East West North
1,592,36777,211Total
845,98442,374Beverage
746,38334,837Food
RevenueUnits SoldProduct
or
0 20 40 60 80
Marketing
Operations
Finance
Sales
andwhich kind?
Either
Match the display to your message
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
25
Eeney, meeney, miney, moe what type of display should I use this time?
or
Used to look up individual values
Tables work best when
Used to compare individual values Data must be precise You must include multiple units of measure
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
26
What do graphs do best?
Graphs show relationships between values by giving them shape.
Graphs bring relationships to light
Whats the message?
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
27
Quantitative messages always involve relationships.
Relationship? Time Series
Time
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
28
RankingRelationship?
1
2
3
4
5
6
7
8
Part-to-WholeRelationship?
+ + + =100%
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
29
DeviationRelationship?
DistributionRelationship?
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
30
CorrelationRelationship?
Nominal ComparisonRelationship?
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
31
Nominal comparison Time-series Ranking Part-to-whole Deviation Distribution Correlation
The seven common relationships in graphs
Whats the other half?
Knowing the right medium is half the battle.
Designing each component to speak clearly.
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
32
The power of visual perception
70% 30%
Visual perception is not just camera work
Square A is darker than B, right?
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
33
We perceive differences, not absolutes
Take a closer look
Context affects visual perception
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
34
Save the pies for dessert!
What about grid lines in graphs?
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
35
What about 3-D? Its so cute!!!
But what if theres a 3rd variable?
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
36
Can you ever show too much?
Is more color always better?
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
37
Color choices make a difference
Business intelligence and data visualization
Emphasis on technology Emphasis on human ability
Show Me the Numbers: Communicating Effectively with ChartsStephen Few, Perceptual Edge
The DAMA International Symposium & WILSHIRE Meta-Da ta ConferenceDenver, Colorado April 23-27, 2006
38
You have a choice to make!
To communicate
or not to communicate,
that is the question!