The Practice of Social Research

Chapter 14 – Quantitative Data Analysis

Chapter Outline Quantification of Data Univariate Analysis Subgroup Comparisons Bivariate Analysis Introduction to Multivariate Analysis Sociological Diagnostics Ethics and Quantitative Data Analysis Quick Quiz

Quantification of Data Quantification Analysis – the numerical

representation and manipulation of observations for the purpose of describing and explaining the phenomena that those observations reflect.

Quantification of Data Age

1 = 1 2 = 2 3 = 3 4 = 4 5 = 5

Sex Male = 1 Female = 2

Political Affiliation Democrat = 1 Republican = 2 Independent = 3

Region of Country West = 1 Midwest = 2 South = 3 Northeast = 4

Quantification of Data Develop Code Categories

1. Use well-developed coding scheme.

2. Generate codes from your data.

Quantification of Data Codebook Construction

Codebook – the document used in data processing and analysis that tells the location of different data items in a data file. The codebook also identifies the locations of data items and the

meaning of the codes used.

Purposes of the Codebook1. Primary guide in the coking processes

2. Guide for locating variables

ATTENDHow often do you attend religious services?

0. Never1. Less than once a year2. About once or twice a year3. Several times a year4. About once a month5. 2-3 times a month6. Nearly every week7. Every week8. Several times a week9. Don’t know, No answer

Abbreviated Variable NameN

umer

ical

Lab

le

Definition of the Variable

Variable Attributes

Univariate Analysis Univariate Analysis – the analysis of a single

variable, for purposes of description (examples: frequency distribution, averages, and measures of dispersion).

Example: Gender The number of men in a sample/population and the number of

women in a sample/population.

Univariate Analysis Distributions

Frequency Distributions – a description of the number of times the various attributes of a variable are observed in a sample.

Univariate Analysis Central Tendency

Average – an ambiguous term generally suggesting typical or normal – a central tendency (examples: mean, median, mode).

Univariate Analysis Mean – an average computed by summing the

values of several observations and dividing by the number of observations.

Mode- an average representing the most frequently observed value or attribute.

Median – an average representing the value of the “middle” case in a rank-ordered set of observations.

Univariate Analysis Practice: The following list represents the scores on

a mid-term exam.

100, 94, 88, 91, 75, 61, 93, 82, 70, 88, 71, 88

Determine the mean.

Determine the mode.

Determine the median.

Univariate Analysis Dispersion – the distribution of values around some

central value, such as an average.

Standard Deviation – a measure of dispersion around the mean, calculated so that approximately 68 percent of the cases will lie within plus or minus one standard deviation from the mean, 95 percent within two, and 99.9 percent within three standard deviations.

Univariate Analysis Continuous Variable – a variable whose attributes

form a steady progression, such as age of income.

Discrete Variable – a variable whose attributes are separate from one another, such as gender or political affiliation.

Univariate Analysis Detail versus Manageability

Provide reader with fullest degree of detail, balanced with presenting data in a manageable form.

Subgroup Comparisons Description of subsets of cases, subjects or

respondents.

“Collapsing” Response Categories

Handling “Don’t Knows”

Bivariate Analysis Bivariate Analysis – the analysis of two variables

simultaneously, for the purpose of determining the empirical relationship between them.

Bivariate Analysis Constructing a Bivariate Table

1. Determine logical direction of relationship (independent variable and dependent variable).

2. Percentage down versus percentage across.

Bivariate Analysis Constructing and Reading Bivariate Tables

Example: Gender and Attitude toward Sexual Equality1. The cases are divided into men and women.

2. Each gender subgroup is described in terms of approval or disapproval of sexual equality.

3. Men and women are compared in terms of the percentages approving of sexual equality.

Bivariate Analysis Contingency Table – a format for presenting the

relationship among variables as percentage distributions.

Bivariate Analysis Guidelines for Presentation of Tables

1. A table should have a heading or title that describes what is contained in the table.

2. Original content should be clearly presented.

3. The attributes of each variable should be clearly indicated.

4. The base on which percentage are computed should be indicated.

5. Missing data should be indicated in the table.

Introduction to Multivariate Analysis Multivariate Analysis – the analysis of the

simultaneous relationships among several variables.

Quick Quiz

Chapter 14 Quiz

1. To conduct a quantitative analysis, researchers often must engage in a _____ after the data have been collected.

A. coding process

B. case-oriented analysis

C. experimental analysis

D. field research study

Chapter 14 Quiz

Answer: A.

To conduct a quantitative analysis, researchers often must engage in a coding process after the data have been collected.

Chapter 14 Quiz

2. Which of the following describes the analysis of more than two variables?

A. experimental designs

B. quasi-experimental designs

C. qualitative evaluations

D. multivariate analysis

Chapter 14 Quiz

Answer: D.

Multivariate analysis describes the analysis of more than two variables.

Chapter 14 Quiz

3. The process of converting data to numerical format is called _____.

A. feminist research

B. qualification

C. quantification

Chapter 14 Quiz

ANSWER: C.

The process of converting data to numerical format is called quantification.

Chapter 14 Quiz

4. Which of the following are basic approaches to the coding process?

A. You can begin with a well developed coding scheme.

B. You can generate codes from your data.

C. both of the above

D. none of the above

Chapter 14 Quiz

ANSWER: C.

The following are basic approaches to the coding process: you can begin with a well developing coding scheme and/or you can generate codes from your data.

Chapter 14 Quiz

5. A _____ is a document that describes the locations of variables and lists the assignments of codes to the attributes composing those variables.

A. cross-case analysis

B. codebook

C. constant comparative method

D. monitoring study

Chapter 14 Quiz

ANSWER: B.

A codebook is a document that describes the locations of variables and lists the assignments of codes to the attributes composing those variables.

Chapter 14 Quiz

6. The _____ is an average computed by summing the values of several observations and divided by the number of observations.

A. frequency

B. mean

C. median

D. mode

Chapter 14 Quiz

ANSWER: B.

The mean is an average computed by summing the values of several observations and divided by the number of observations.