Chapter 2Organizing the Data

Nominal Data and Distributions

Responses of Young Boys to Removal of Toy

Response of Child fCry 25Express Anger 15Withdraw 5Play with another toy 5

N=50

Frequency distribution of nominal data consists of two columns:

• Left column has characteristics (e.g., Response of Child)

• Right column has frequency (f)

Comparing Distributions• Comparisons clarify and add information

Response to Removal of Toy by Gender of Child

Gender of ChildResponse of Child Male FemaleCry 25 14Express Anger 15 1Withdraw 5 2Play with another toy 5 8 Total 50 25

Illustration: Gender of Students Majoring in CJ(f)

Criminal Justice Majors

Gender College A College BMale 879 119Female 473 64Total 1,352 183

Illustration: Gender of Students Majoring in CJ (f and

%)Criminal Justice Majors

College A College B

Gender

f % f %

Male 879 65 119 65

Female

473 35 64 35

Total 1,352 100 183 100

Rate of Change• Compare the same

population at two points in time

• Rate of Change = time 2f – time1f time 1f

(100)*

Year Theft Rate1

% Change

2005 120.32006 127.42007 116.82008 107.42009 98.72010 94.6

1Source: National Crime Victimization Survey

Ordinal/Interval Data and Distributions

Attitudes Toward Televised Trials

FSlightly Favorable 9Somewhat Unfavorable 7Strongly Favorable 10Slightly Unfavorable 6Strongly Unfavorable 12Somewhat Favorable 21Total 65

Attitudes Toward Televised Trials

FStrongly Favorable 10Somewhat Favorable 21Slightly Favorable 9Slightly Unfavorable 6Somewhat Unfavorable 7Strongly Unfavorable 12Total 65

Frequency Distribution of Final-Examination Grades for 71 StudentsGrade f Grade f Grade f Grade f99 0 85 2 71 4 57 0

98 1 84 1 70 9 56 1

97 0 83 0 69 3 55 0

96 1 82 3 68 5 54 1

95 1 81 1 67 1 53 0

94 0 80 2 66 3 52 1

93 0 79 8 65 0 51 1

92 1 78 1 64 1 50 1

91 1 77 0 63 2 N = 71

90 0 76 2 62 0

89 1 75 1 61 0

88 0 74 1 60 2

87 1 73 1 59 3

86 0 72 2 58 1

Grouped Frequency Distributions of Interval DataGrouped Frequency Distribution of Final-Examination Grades for 71 Students

Class Interval f %95-99 390-94 285-89 480-84 775-79 1270-74 1765-69 1260-64 555-59 550-54 4

Flexible Class IntervalsIncome Category F %

$100,000 and above 16,886 21.9$75,000-$99,999 10,471 13.5$50,000-$74,000 15,754 20.3$40,000-$49,999 7488 9.7$30,000-$39,999 7996 10.3$20,000-$29,999 8169 10.6$15,000-$19,999 3709 4.8$10,000-$14,999 2890 3.7$5001-$9999 2024 2.6Under $5000 2031 2.6

N = 77688

Grouped Frequency Distributions of Interval DataGrouped Frequency Distribution of Final-Examination Grades for 71 Students

Class Interval f Cf % C%95-99 3 4.2390-94 2 2.8285-89 4 5.6380-84 7 9.8675-79 12 16.9070-74 17 23.9465-69 12 16.9060-64 5 7.0455-59 5 7.0450-54 4 . 5.63

Grouped Frequency Distributions of Interval DataGrouped Frequency Distribution of Final-Examination Grades for 71 Students

Class Interval f Cf % C%95-99 3 71 4.23 10090-94 2 68 2.82 95.7685-89 4 66 5.63 92.9480-84 7 62 9.86 87.3175-79 12 55 16.90 77.4570-74 17 43 23.94 60.5565-69 12 26 16.90 36.3160-64 5 14 7.04 19.7155-59 5 9 7.04 12.6750-54 4 4 5.63 5.63

71 100

Chapter 2 Day 2

Frequency Distribution of Seat Belt UseUse of Seat Belts f %All the time 499 50.1Most of the time 176 17.7Some of the time 124 12.4Seldom 83 8.3Never 115 11.5 Total 997 100

Cross-tabCross-Tabulation of Seat Belt Use by Gender

Gender of Respondents

Use of Seat Belts Male Female TotalAll the time 144 355 499Most of the time 66 110 176Some of the time 58 66 124Seldom 39 44 83Never 60 55 115 Total 367 630 997

Cross Tabulations – Victim-Offender Relationship by Gender of Victim for

Homicides in US for 2005 (With Row%)Victim-Offender Relationship

Gender Intimate Intimate % Family Family % Other Other % Total Total %

Male 617 1,310 11,235 13,161

Female 1,470 639 1,421 3,531

Total 2,087 1,949 12,656 16,692

Cross Tabulations – Victim-Offender Relationship by Gender of Victim for

Homicides in US for 2005 (With Row%)Victim-Offender Relationship

Gender Intimate Intimate % Family Family % Other Other % Total Total %

Male 617 4.7% 1,310 10.0% 11,235 85.4% 13,161 100%

Female 1,470 41.6% 639 18.1% 1,421 40.2% 3,531 100%

Total 2,087 12.5% 1,949 11.7% 12,656 75.8% 16,692 100%

Cross Tabulations – Victim-Offender Relationship by Gender of Victim for

Homicides in US for 2005 (With Row%)Age

Juvenile Juvenile % Adult Adult % Total Total %

Person 45 228 273

Property 117 194 311

Other 225 204 429

Total 387 626 1013

Cross Tabulations – Victim-Offender Relationship by Gender of Victim for

Homicides in US for 2005 (With Row%)Age

Juvenile Juvenile % Adult Adult % Total Total %

Person 45 11.63% 228 36.42% 273 26.95%

Property 117 30.23% 194 30.99% 311 30.7%

Other 225 58.14% 204 32.59% 429 42.35%

Total 387 100% 626 100% 1013 100%

Pie Chart

Exploded Pie Chart

Weapon Used

FirearmNon-firearmNone

Bar GraphBar Graph of Seat Belt Use by Gender (with percents)

0

10

20

30

40

50

60

70

Never Seldom Sometimes Most times All times

Seat belt use

Perc

ent

MaleFemale

Histogram of Distribution of Children in Little Rock Community Survey

Frequency Polygon for Distribution of Student Examination Grades

0

5

10

15

20

52 57 62 67 72 77 82 87 92 97

Midpoint

Fre

quen

cyFrequency Polygon Example

Janua

ry

Febru

aryMarc

hAp

ril May June Jul

yAu

gust

Septe

mber

Octobe

r

Novem

ber

Decembe

r0

2000

4000

6000

8000

10000

12000

14000

MarijuannaAlcoholHallucinogens

Number of Adolescents (< 18 y/o) Using for the First Time by Month

Kurtosis

Leptokurtic Platykurtic Mesokurtic

Some Variation in Kurtosis among Symmetrical Distributions

Skewness

Negatively skewed Positively skewed Symmetrical(Normal)

Three Distributions Representing Direction of Skewness