Bureau of Justice Statistics Tables should
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Transcript Bureau of Justice Statistics Tables should
Data presentation
A guide to good tables
Bureau of Justice Statistics
October 11, 2000
Marianne W. Zawitz
[email protected]
Elements of a table
Table 1. Number of widgets
and gadgets by color
Color
Total
Blue
Red
Green*
20
28
18
* True color is aqua not green.
Bureau of Justice Statistics
Number
Widgets Gadgets
14
23
3
6
5
15
Elements of a table
Table 1. Number of widgets
and gadgets by color
{
Stub
Color
Total
Blue
Red
Green*
20
28
18
* True color is aqua not green.
Bureau of Justice Statistics
Number
Widgets Gadgets
14
23
3
6
5
15
Elements of a table
Table 1. Number of widgets
and gadgets by color
Color
Total
Blue
Red
Green*
20
28
18
* True color is aqua not green.
Bureau of Justice Statistics
Header
Number
Widgets Gadgets
14
23
3
6
5
15
Elements of a table
Table 1. Number of widgets Spreader Head
and gadgets by color
Color
Total
Blue
Red
Green*
20
28
18
* True color is aqua not green.
Bureau of Justice Statistics
Number
Widgets Gadgets
14
23
3
6
5
15
Elements of a table
Table 1. Number of widgets
and gadgets by color
Color
Total
Blue
Red
Green*
20
28
18
* True color is aqua not green.
Bureau of Justice Statistics
Number
Data field
Widgets Gadgets
14
23
3
6
5
15
Elements of a table
Table 1. Number of widgets
and gadgets by color
Color
Total
Blue
Red
Green*
20
28
18
* True color is aqua not green.
Bureau of Justice Statistics
Number
Widgets Gadgets
14
23
3
6
5
15
Cell
Elements of a table
Table 1. Number of widgets
and gadgets by color
Color
Total
Blue
Red
Green*
20
28
18
* True color is aqua not green.
Bureau of Justice Statistics
Number
Widgets Gadgets
14
23
3
6
5
15
Row
Elements of a table
Table 1. Number of widgets
and gadgets by color
Color
Total
Blue
Red
Green*
20
28
18
* True color is aqua not green.
Bureau of Justice Statistics
Number
Widgets Gadgets
14
23
3
6
5
15
Column
Elements of a table
Title
Table 1. Number of widgets
and gadgets by color
Color
Total
Blue
Red
Green*
20
28
18
* True color is aqua not green.
Bureau of Justice Statistics
Number
Widgets Gadgets
14
23
3
6
5
15
Elements of a table
Table 1. Number of widgets
and gadgets by color
Notes
Color
Total
Blue
Red
Green*
20
28
18
* True color is aqua not green.
Bureau of Justice Statistics
Number
Widgets Gadgets
14
23
3
6
5
15
Use tables, when you need to present 10 or fewer data points
to find exact numeric values
to make localized comparisons
Bureau of Justice Statistics
Tables have an architecture
Use the structure of the table to
reinforce its purpose
Take advantage of how we learned
to do math
Bureau of Justice Statistics
327 483 123 42
327
483
123
42
7
18
Bureau of Justice Statistics
7 18
XXXX
XXX
XX
X
Bureau of Justice Statistics
Types of tables Exploratory tables
Resource tables
Presentation tables
Bureau of Justice Statistics
Example of an exploratory table
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
12 and
under
6.7
6.7
7.2
6.8
7.5
7.4
8.2
7.2
7.2
9.3
9.5
8.9
12.7
13.9
13-14
15
16
17
18
19
20
21
122
126.3
138.4
128.5
130.8
141.2
165.6
166.9
163.5
180.1
206.5
221.2
280.6
316.5
236
251
262.5
266.6
245.5
267.1
302.9
297.3
295.8
343.9
391.8
416.7
518.4
559
326.4
319.4
339.7
336.9
316.3
336.5
374.6
388.7
368.8
435.5
531.7
553.9
669.7
724.1
404
400.8
406
420.9
393.4
414.8
444.3
476.4
458.4
541.2
640.2
661.8
775.1
802.9
472.1
457.5
460.9
471.6
433.2
468.7
501.2
560.5
548.3
634.8
704.8
756.3
886.6
920.1
425
429.9
450.5
465.8
413.4
433.6
469.5
508.9
516.1
558.5
638
632.3
725.2
777.6
400.9
399.6
407
443.5
393.6
392.4
418.9
484.3
469.8
509.9
541.9
546.5
601.9
651.5
403.9
407.4
410.9
432.1
399.8
410
415
468.6
474
497.1
543.2
521.4
591.4
610.8
Bureau of Justice Statistics
Resource table
State
Number of
agencies
Full-time
employees
Full-time
sworn officers
All States
18,769
921,978
663,535
Alabama
Alaska
Arizona
Arkansas
California
432
69
130
360
524
14,389
1,884
16,828
7,958
103,967
9,767
1,254
10,088
5,819
69,134
Colorado
Connecticut
Delaware
District of Columbia
Florida
247
129
45
3
385
14,002
10,319
2,134
4,651
60,808
9,896
8,525
1,660
3,909
37,395
Bureau of Justice Statistics
Presentation table
Homicides of children under age 5
Relationship
with child
Father
Acquaintance
Mother
Other family
Stranger
Bureau of Justice Statistics
Percent of
perpetrators
32%
30
28
6
4
Tables should - Show the data
Reduce nondata ink
Avoid puzzles
Create a logical visual pattern
Use the same standards for verbal
elements we use in graphics
Bureau of Justice Statistics
Excess lines and marks make
the data hard to see
State
Full-time
employees
Number of
agencies
Full-time
sworn officers
All States ...................
18,769
921,978
663,535
Alabama ....................
Alaska ........................
Arizona ......................
Arkansas ...................
California ...................
432
69
130
360
524
14,389
1,884
16,828
7,958
103,967
9,767
1,254
10,088
5,819
69,134
Colorado ....................
Connecticut ...............
Delaware ....................
District of Columbia .
Florida .......................
247
129
45
3
385
14,002
10,319
2,134
4,651
60,808
9,896
8,525
1,660
3,909
37,395
Bureau of Justice Statistics
Without the lines the data are
the focus of the table
State
Number of
agencies
Full-time
employees
Full-time
sworn officers
All States
18,769
921,978
663,535
Alabama
Alaska
Arizona.
Arkansas
California
432
69
130
360
524
14,389
1,884
16,828
7,958
103,967
9,767
1,254
10,088
5,819
69,134
Colorado
Connecticut
Delaware
District of Columbia
Florida
247
129
45
3
385
14,002
10,319
2,134
4,651
60,808
9,896
8,525
1,660
3,909
37,395
Bureau of Justice Statistics
Keep decimal places to a minimum
They imply false precision
(often they are not significant)
They pad the numbers making
them bigger than they really are
Use only as many decimal places
as needed to break a tie
Bureau of Justice Statistics
With fewer decimal
This table has too
places, it is easier
many decimal places to read
Homicides of children
under age 5
Male perpetrators
Male victim
Female victim
Female perpetrators
Male victim
Female victim
67.8697%
21.9989%
7.7851%
2.3463%
Homicides of children
under age 5
Male perpetrators
Male victim
68 %
Female victim
22
Female perpetrators
Male victim
8
Female victim
2
The numbers were different enough
that decimal places were not needed
Bureau of Justice Statistics
Presentation tables should - Reduce the data presented
Not present everything to show that
it all adds up
Use only one of the two variables
when presenting binary data
Bureau of Justice Statistics
Order the content according to
how the data will be used
Presentation tables use rank order
or another hierarchy
-- Look to the numbers to carry out
the ordering
Resource tables use alphabetical
or reference order
Bureau of Justice Statistics
Rank order in presentation tables
reveals the structure of the data
Homicides of children under age 5
Relationship
with child
Father
Acquaintance
Mother
Other family
Stranger
Bureau of Justice Statistics
Percent of
perpetrators
32%
30
28
6
4
Order resource tables alphabetically
or in another meaningful manner
State
Number of
agencies
Full-time
employees
Full-time
sworn officers
All States
18,769
921,978
663,535
Alabama
Alaska
Arizona.
Arkansas
California
432
69
130
360
524
14,389
1,884
16,828
7,958
103,967
9,767
1,254
10,088
5,819
69,134
Colorado
Connecticut
Delaware
District of Columbia
Florida
247
129
45
3
385
14,002
10,319
2,134
4,651
60,808
9,896
8,525
1,660
3,909
37,395
Bureau of Justice Statistics
Structure the table to - make patterns and exceptions
obvious at a glance
place numbers that are to be
compared close to one another
(in a column is best)
place summary data where it will
be most useful
Bureau of Justice Statistics
This structure makes it difficult to
compare the same units
ITEM
1990
1995
1996
Number Percent Number Percent Number Percent
TYPES OF
SUBSTANTIATED
MALTREATMENT/1
Victims, total
Neglect
Physical abuse
Sexual abuse
Emotional
maltreatment
Medical Neglect
Other and
unknown
690,658
(X)
970,285
(X)
969,018
338,770
49.1
507,015
52.3
500,032
186,801
27
237,840
24.5
229,332
119,50617.3
122,964
12.7
119,39712.3
(X)
51.6
23.7
45,621
(NA)
6.6
(NA)
42,051
28,541
4.3
2.9
55,473
5,758
5.7
2.7
61,477
8.9
157,819
16.3
175,613
18.1
Bureau of Justice Statistics
A revision puts the numbers that are
to be compared close together
TYPES OF
SUBSTANTIATED
MALTREATMENT/1
Number of victims
Victims, total
Neglect
Physical abuse
Sexual abuse
Emotional
maltreatment
Medical Neglect
Other and
unknown
Percent of all victims
1990
1995
1996
1990
1995
1996
-------------------------------------- -------------------------------------690,658 970,285 969,018
100.0% 100.0% 100.0%
338,770 507,015 500,032
49.1
52.3
51.6
186,801 237,840 229,332
27.0
24.5
23.7
119,506 122,964 119,397
17.3
12.7
12.3
45,621
...
55,473
25,758
6.6
4.3
2.9
5.7
2.7
61,477 157,819 175,613
8.9
16.3
18.1
Bureau of Justice Statistics
42,051
28,541
A better way to restructure this table
is to make the annual comparisons up
and down
Neglect
Physical
abuse
Sexual
abuse
Emotional
maltreat- Medical
ment
Neglect
690,658
970,285
969,018
338,770
507,015
500,032
186,801
237,840
229,332
119,506
122,964
119,397
45,621
42,051
55,473
...
28,541
25,758
61,477
157,819
175,613
100.0%
100.0
100.0
49.1%
52.3
51.6
27.0%
24.5
23.7
17.3%
12.7
12.3
6.6%
4.3
5.7
...
2.9
2.7
8.9%
16.3
18.1
Year
Victims,
total
Number
1990
1995
1996
Percent
1990
1995
1996
Bureau of Justice Statistics
Other and
unknown
Notation should - be placed in the row labels and
column headers if possible (otherwise
they interfere with our ability to see
the data)
not be numeric characters so they
are not confused with the numbers
Bureau of Justice Statistics
Notation in this table interferes with
your ability to compare the numbers
ITEM
1990
1995
1996
Number Percent Number Percent Number Percent
TYPES OF
SUBSTANTIATED
MALTREATMENT/1
Victims, total
Neglect
Physical abuse
Sexual abuse
Emotional
maltreatment
Medical Neglect
Other and
unknown
690,658
(X)
970,285
(X)
969,018
338,770
49.1
507,015
52.3
500,032
186,801
27
237,840
24.5
229,332
119,50617.3
122,964
12.7
119,39712.3
(X)
51.6
23.7
45,621
(NA)
6.6
(NA)
42,051
28,541
4.3
2.9
55,473
5,758
5.7
2.7
61,477
8.9
157,819
16.3
175,613
18.1
Bureau of Justice Statistics
Lighter notation conveys information
without interfering
TYPES OF
SUBSTANTIATED
MALTREATMENT/1
Number of victims
Victims, total
Neglect
Physical abuse
Sexual abuse
Emotional
maltreatment
Medical Neglect
Other and
unknown
Percent of all victims
1990
1995
1996
1990
1995
1996
-------------------------------------- -------------------------------------690,658 970,285 969,018
100.0% 100.0% 100.0%
338,770 507,015 500,032
49.1
52.3
51.6
186,801 237,840 229,332
27.0
24.5
23.7
119,506 122,964 119,397
17.3
12.7
12.3
45,621
...
55,473
25,758
6.6
...
4.3
2.9
5.7
2.7
61,477 157,819 175,613
8.9
16.3
18.1
Bureau of Justice Statistics
42,051
28,541
Avoid tables with many empty cells
and don’t use notation for true 0’s
State
Number
admitted
Number
executed
Number
removed
All States
--
--
--
Alabama
Alaska
Arizona
Arkansas
California
------
------
------
Colorado
Connecticut
Delaware
District of Columbia
Florida
------
------
------
Bureau of Justice Statistics
-- see page 27.
Rows should - have consistent labeling from
table to table
indent the labels to show
subdivisions (nesting)
create patterns with a line or half
line skip every fifth entry in long
lists
Bureau of Justice Statistics
Label nesting shows relationships
Homicides of children
under age 5
Male perpetrators
Male victim
Female victim
Female perpetrators
Male victim
Female victim
68 %
22
8
2
Columns should - contain the same unit of measure
have labels that clearly identify
what is measured (both numerator
and denominator for rates or
percentages)
avoid repetitious categories by
spacing and grouping
Bureau of Justice Statistics
Mixing units of analysis compares apples to oranges
(or dogs to cats)
No. 431. Household Pet Ownership by
Selected Characteristics
ITEM
Unit
Dog
Cat
1996: Households owning companion pets \1 Million
4.6
1.5
Percent of all households
Percent
4.6
1.5
Average number owned
Number
2.7
2.7
Total companion pet population \1
Million
12.6
4
Households obtaining veterinary care \2
Average visits per household per year
Percent
Number
15.8
0.2
66.3
2.3
Average annual costs per household
Dollars
10.95
226.26
Total expenditures
Mil. dol.
50
339
Source: Statistical Abstracts of the United States
Bureau of Justice Statistics
Avoid large gaps between the stub and
first column
Full-time
employees
State
Full-time
sworn officers
All States
921,978
663,535
Alabama
Alaska
Arizona
Arkansas
California
14,389
1,884
16,828
7,958
103,967
9,767
1,254
10,088
5,819
69,134
14,002
10,319
2,134
4,651
60,808
9,896
8,525
1,660
3,909
37,395
Colorado
Connecticut
Delaware
District of Columbia
Florida
Bureau of Justice Statistics
the grand canyon
A few additional thoughts
Use no more than 9 columns in a
table
Add clues regarding the unit of
analysis next to the first number
(%, months, widgets, etc.)
Bureau of Justice Statistics
Make all verbal tasks easy to
understand
Do not use abbreviations
Avoid acronyms
Write all labels left to right
Use proper grammar
Bureau of Justice Statistics
Table titles should - briefly describe the data presented
highlight the difference between this
table and others in the first words
be long enough to inform but short
enough not to bore
Bureau of Justice Statistics