© 2004 demographic perspectives w 1 effective tables and charts important elements of graphic...
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© 2004 Demographic Perspectives www.dem-
perspectives.com
1
Effective Tables and Charts
Important Elements of Graphic Presentation
of Data
Rena Cheskis-Gold
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perspectives.com
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Part I. Charting Data
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Basic Table
Division % Male# Col. % # Col. % # Col. % Row %
Nat. Science 126 42% 110 35% 236 39% 53%
Social Science 108 36% 120 39% 228 37% 47%
Humanities 66 22% 80 26% 146 24% 45%
Total 300 100% 310 100% 610 100% 49%
Male Female Total
Students by Gender by Major Division
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Bar Charts • Quickly compare one category to another.
Male Students Percentage by Major Division,
42%36%
22%
0%
10%
20%
30%
40%
50%
60%
70%
Natural Science Social Science Humanities
% o
f All
Mal
e S
tud
ents
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Pie Charts•Less flexible than bar charts.
•Must include all categories and add to 100%.
Percent of Students in Each Major Division
42%
36%
22% NaturalScienceSocial Science
Humanities
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When there is a second layer of information, you must use a bar chart.
Major Division,% of Students Who are Male
53%47% 45%
0%
10%
20%
30%
40%
50%
60%
70%
Natural Science Social Science Humanities
% M
ale
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Bar charts are useful for more complex comparisons.
Percent Very Satisfied, by Major Division,Gallilee College vs. Arad University
41%36%
55%
34%
24%
44%
0%
10%
20%
30%
40%
50%
60%
70%
Natural Science Social Science Humanities
Gallilee Arad
Students in every major division are significantly more satisfied at Gallilee College.
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Comparing Distributions:Males to Females
Satisfaction with Courses in Major Divisions, Males vs. Females
50%55%
44%
56%50% 50%
0%
10%
20%
30%
40%
50%
60%
70%
Natural Science Social Science Humanities
% S
atis
fied
Male
Female
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Comparing Divisions
Satisfaction with Courses in Major Divisions, by Division, for Males and Females
50%56%55%
50%44%
50%
0%
10%
20%
30%
40%
50%
60%
70%
Male Female
% S
atis
fied
Natural Science Social Science Humanities
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Time PlotsNumber of Students Withdrawing
in First Semester
35
23
1210
0
5
10
15
20
25
30
35
40
September October November December
# of S
tude
nts
Number of Students Withdrawing in First Semester
35
23
1210
0
5
10
15
20
25
30
35
40
September October November December
# of S
tude
nts
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Cumulative Time Plot
Cumulative Number of Students Withdrawing in First Semester
35
58
70
80
0
10
20
30
40
50
60
70
80
90
September October November December
Cum
ulat
ive
# of
Stu
dent
s
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Box Plots
• To Summarize Large Amounts of Information2002 Senior Survey Advising
Satisfaction Scores for Galillee College and 5 Peer Schools
Advising Before Major Advising in Major In Major, Quality of Advising1.0
1.5
2.0
2.5
3.0
3.5
4.0
High/Low Median Galillee
Note: On a scale from (1) Very Dissatisfied; (2) Generally Dissatisfied; (3) Generally Satisfied; (4) Very Satisfied.
Demographic Perspectives 9-20-02
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Part II. Statistical Thinking
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When to chart or not?
1. Enough variation to chart?
2. Makes sense to chart?
3. Interesting enough to chart?
4. Precise enough to chart?
5. Enough information to draw a conclusion?
6. Is a chart the best way?
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Is there enough variation to warrant a chart?
Satisfaction with Courses in Major Divisions, by Division, for Males and Females
50% 51%49% 50%51% 48%
0%
10%
20%
30%
40%
50%
60%
70%
Male Female
% S
atis
fied
Natural Science Social Science Humanities
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Will the comparison make sense if charted?
Increase in Endowment Over Five Years
$250,000,000
$10,000 $15,000
$300,000,000
$0
$50,000,000
$100,000,000
$150,000,000
$200,000,000
$250,000,000
$300,000,000
$350,000,000
Arad University Galilee College Hilltop College University ofNorthwest
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Are the data interesting enough to chart?
Percent of Students in Each Major Division
26%
35%39%
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
Natural Science Social Science Humanities
% o
f St
uden
ts
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Are the data precise enough to chart?
Percent Very Satisfied, by Major Division,Gallilee College vs. University of Arad
40.5%35.9%
55.2%
33.9%
23.5%
44.4%
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
Natural Science Social Science Humanities
Gallilee Arad
Students in every major division are significantly more satisfied at Gallilee College.
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Is a chart the best way to display these data?
Q8. Quality of Academic ExperienceScale: 1 = Very dissatisfied; 4 = Very satisfied
1.8
2.3
2.5
2.8
2.7
2.7
3.0
3.1
3.1
2.9
3.1
2.1
2.2
2.5
2.7
2.9
2.9
2.9
3.0
3.0
3.1
3.1
3.2
1.0 1.5 2.0 2.5 3.0 3.5 4.0
Study off-campus or abroad
Academic advising before declaring major
Academic advising in your major
Internships
Out of class faculty availability
Class size
Tutorial help or academic assistance
Interdisciplinary courses
Opportunity to participate in research with faculty member
Course availability
Independent study, self-designed courses
Quality of instruction
Mean Satisfaction
2002
1998
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Part III.Effective Presentation
of Data
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Importance of an Effective Data Presentation
• The desired effect is not ‘data,’ but ‘information.’
• A good appearance will not disguise bad data, but a bad appearance may minimize your good efforts.
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Why Do We Need to Understand Graphic Design?
• To have the correct vocabulary to communicate with design professionals
• To work efficiently and produce better quality documents
• Good design is “intelligence made visible”
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Project Background Questions
• What are the expectations of the audience? What is their level of sophistication?
• How will the document be used?
• What are the available resources and timetable?
• How and where will the document be printed, and are there cost limitations?
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Basic Graphic Design Elements
1. Unity2. Variety3. Design a Page Grid4. Group Related Items5. Establish Clear Alignments6. Repeat Visual Elements7. Utilize Strong Contrasts8. Choose Appropriate Fonts
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Style Considerations
1. Size
2. Reproduction
3. Lines
4. Level of Precision
5. Over-label
6. Choosing Your Style
7. Abbreviations
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“Although we often hear that data
speak for themselves, their voices
can be soft and sly.”
Mosteller, F. Beginning Statistics with Data Analysis. 1983.
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• Using ‘chart junk’
• No relative basis in comparing data batches
• Compressing the Vertical axis
• No zero point on the
vertical axis
Conceptual Errors in Presenting Data
Anna Waggener, U.S. Army War College
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‘Chart Junk’ and Lie Factor
Good Presentation
1960: $1.00
1970: $1.60
1980: $3.10
1990: $3.80
Minimum Wage Minimum Wage
0
2
4
1960 1970 1980 1990
$
Bad Presentation
Source: Anna Waggener
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No Relative Basis
Good PresentationA’s received by
students.A’s received by
students.
Bad Presentation
0
200
300
FR SO JR SR
Freq.
10%
30%
FR SO JR SR
%
Source: Anna Waggener
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No Zero Point on Vertical Axis
Good Presentation
Monthly Expenses Monthly Expenses
Bad Presentation
0
20
40
60
J F M A M J
$
36
39
42
45
J F M A M J
$
Graphing the first six months of sales.
Source: Anna Waggener
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More Errors in Presenting Data
1. Inappropriate use of depth
2. Poor labeling
3. Too small or too crowded
4. Bad translation from color to black and white
5. Not enough information
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Especially Annoying Errors in Presenting Data
1. Usage of abbreviations, especially computer variables
2. Superfluous ‘tick’ marks
3. Vibration
4. Unnecessary precision
5. Data hiding in text form
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Using Fonts in Presentations
1. Pick the right font for the message.
2. Serif fonts (Times New Roman) vs. Sans Serif fonts (Arial).
3. Use bold, italics, and color carefully.
4. Consistency is important.
Source: Microsoft Powerpoint.
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Typical Powerpoint Default Chart
0
10
20
30
40
50
60
70
80
90
1st Qtr 2nd Qtr 3rd Qtr 4th Qtr
East
West
North
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Better Version of Default Chart
2027
20
3139
35 32
46 47 45 44
90
0
20
40
60
80
100
1st Qtr 2nd Qtr 3rd Qtr 4th Qtr
Sales Quarter
Wid
gets
East West North
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For help or information, contact
Rena Cheskis-Gold, (203) 397-1612