A Picture is Worth a Thousand Words Presenting Data in Telling Your Story

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A Picture is Worth a Thousand WordsPresenting
Data in Telling Your Story

• Alan Moghul, Ph.D.
• CADCA National Leadership Forum XVI
• Washington, DC
• February 16, 2006

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Some general rules

• The graphic should be intuitively understandable.
• The graphic should prove your point.
• Pick the appropriate format (e.g., pie chart,
  scattergram, bar chart, etc.)
• Label everything.

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Your graphic should be intuitively understandable.

• The reader should be able to discern nearly the
  entire story just by looking at the graph.

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What is this graphic telling us?
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What is this graphic telling us?

• Drinking Trends Among High School Seniors,
  1975-2002

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The graphic should prove your point.

• Is a particular intervention decreasing the age
  of onset?
• Does a particular populations perception of risk
  increase over time?
• What are the rates of use among 3 different
  groups?

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Among eighth graders, the perceived availability
of alcohol has been decreasing over the past
decade.
SOURCE Monitoring the Future 2005
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Be sure to select the appropriate format for your
graphic.

• Pie chart
• Scattergram
• Bar graph
• Table or chart

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Pie chart What percentageof the whole does a
particular attribute represent?
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New HIV Diagnoses, by Race/Ethnicity (2001-2004)
Other 2
Hispanic 18
African-American 51
White 29
Source CDC
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Scattergram --

• Shows a trend..
• How does something
• change over time?

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Binge Drinking Trends Among High School Seniors
(1975-2002)
Source Monitoring the Future, 2002
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Bar graph

• How much (or how
• high) is something
• relative to
• something else?
• How do these items
• change over time?

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Youth Tend to Drink More Heavily than Adults
4.5
2.8
Youth
Adults
SOURCE National Household Survey, 2000
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Number of Units Sold, by Quarter
Explorer Mustang Taurus
NUMBER OF UNITS
QUARTER
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Table or Chart

• Displaying
• information
• by category or
• classification

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Percent of High School Students Who Report Great
Harm in Using Steroids
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Percent of High School Students Who Report Great
Harm in Using Steroids
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SOURCE NASADAD
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And finallyDont forget to LABEL
all parts of the graphic!
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Binge Drinking Trends Among High School Seniors
(1975-2002)
TITLE
LEGEND (if necessary)
Y-AXIS
X-AXIS
ATTRIBUTION
SOURCE Monitoring the Future 2002
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To review

• The graphic should be intuitively understandable.
• The graphic should prove your point.
• Be sure to pick the appropriate format.
• Label all parts of your graphic.

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And now its time for a quiz
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STATEMENT Our data show that the percentage of
12th Graders who have used alcohol in the past 30
days has been steadily declining
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• STATEMENT The ethnic make-up of our school
  district is Caucasian 37 African-American 45
  Hispanic 15 and other groups comprise the rest

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Ethnic Composition of Students in School
District A (2005)
OTHER 3
HISPANIC 15
CAUCASIAN 37
AFRICAN-AMERICAN 45
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STATEMENT Throughout the 4 quarters of 2005, the
average value of Merck stock plummeted, while
Pfizer and SmithKline remained relatively
constant.
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Whats wrong with this graphic?
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The y-axis needs to be labeled.
y-axis label
PERCENT
y-axis scale
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Whats wrong with this graphic?
JC Penney Neiman-Marcus
Dollars (in millions)
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X-axis we need to know more!
JC Penney Neiman-Marcus
Jan 05 Feb 05 Mar 05 Apr 05 May
05
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Thanks for your attention, and best of luck!