Quantitative Data Analysis

1
Chapter 14

• Quantitative Data Analysis

2
Chapter Outline

• Introduction
• Quantification of Data
• Univariate Analysis
• Subgroup Comparisons
• Bivariate Analysis
• Introduction to Multivariate Analysis
• Sociological Diagnostics

3
Quantitative Analysis

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

4
Developing Code Categories

• Two basic approaches
• Beginning with a coding scheme derived from the
  research purpose.
• Generate codes from the data.

5
Student Responses That Can Be Coded Financial
Concerns
6
Question

• To conduct a quantitative analysis researchers
  often must engage in a __________ after the data
  have been collected.
• coding process
• case-oriented analysis
• experimental analysis
• field research study

7
Answer A

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

8
Codebook

• Document that describes the locations of
  variables and lists the assignments of codes to
  the attributes composing those variables.

9
Codebook Construction

• Purposes
• Primary guide used in the coding process.
• Guide for locating variables and interpreting
  codes in the data file during analysis.

10
A Partial Codebook
11
Entering Data

• Data entry specialists enter the data into an
  SPSS data matrix or Excel spreadsheet.
• Optical scan sheets.
• Part of the process of data collection.

12
Quantitative Analysis

• Univariate - simplest formdescribe a case in
  terms of a single variable.
• Bivariate - subgroup comparisons describe a case
  in terms of two variables simultaneously.
• Multivariate - analysis of two or more variables
  simultaneously.

13
Univariate Analysis

• Describing a case in terms of the distribution of
  attributes that comprise it.
• Example
• Gender - number of women number of men.

14
Presenting Univariate Data

• Goals
• Provide reader with the fullest degree of detail
  regarding the data.
• Present data in a manageable from.

15
GSS Attendance at Religious Services 2000
16
Bar Chart of GSS Attend 2000
17
Frequency Distribution

• Description of the number of times that the
  various attributes of a variable are observed in
  a sample.

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Measurement

• AverageMeasure of central tendency.
• MeanResult of diving the sum of the values by
  the total number of cases.

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Measurement

• ModeThe most frequently occurring attribute.
• MedianMiddle attribute in the ranked
  distribution of observed attributes.

20
Three Averages
21
Dispersion

• Refers to the way values are distributed around
  some central value.

22
Standard Deviation

• Index of the amount of variability in a set of
  data.

23
High and Low Standard Deviations
24
Continuous and Discrete Variables

• Continuous variableIncreases steadily in tiny
  fractions.
• Discrete variableJumps from category to category
  without intervening steps.

25
Subgroup Comparisons

• Describe subsets of cases subjects or
  respondents.
• Examples
• Collapsing response categories.
• Handling dont knows.

26
How is the UN doing in solving the problems it
has had to face
27
Collapsing Extreme Categories
28
Handling dont knows
29
Bivariate Analysis

• Describe a case in terms of two variables
  simultaneously.
• Example
• Gender
• Attitudes toward equality for men and women

30
Constructing Bivariate Tables

• Divide cases into groups according to the
  attributes of the independent variable.
• Describe each subgroup in terms of attributes of
  the dependent variable.
• Read the table by comparing independent variable
  subgroups in terms of an attribute of the
  dependent variable.

31
Percentaging a Table

• Some men and women who favor () sexual equality
  or dont (/) favor it.
• Separate the men and the women (the independent
  variable).
• Within each gender group separate those who
  favor equality from those who dont (the
  dependent variable).

32
Percentaging a Table

• Count the numbers in each cell of the table.
• What percentage of the women favor equality
• What percentage of the men favor equality

33
Percentaging a Table

• Conclusions
• While a majority of both men and women favored
  sexual equality women were more likely than men
  to do so.
• Thus gender appears to be one of the causes of
  attitudes toward sexual equality.

34
Church Attendance Reported by Men and Women in
2000
35
Contingency Tables

• Values of the dependent variable are contingent
  on values of the independent variable.

36
Multivariate Analysis

• Analysis of more than two variables
  simultaneously.

37
Multivariate Analysis

• Analysis of more than two variables
  simultaneously.
• Can be used to understand the relationship
  between two variables more fully.

38
Question

• Which of the following describe the analysis of
  more than two variables
• experimental designs
• quasi-experimental designs
• qualitative evaluations
• multivariate analysis
• none of these choices

39
Answer D

• Multivariate analysis describes the analysis of
  more than two variables.

40
Sociological Diagnostics

• Multivariate techniques can be used as powerful
  tools for diagnosing social problems.
• They replace opinions with facts to settle
  ideological debates with data analysis.

41
Quick Quiz
42

• 1. The process of converting data to numerical
  format is called _______________.
• feminist research
• qualification
• quantification
• none of these choices

43
Answer C

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

44

• 2. Which of the following are basic approaches to
  the coding process
• you can begin with a well developed coding scheme
• you can generate codes from your data
• both a and b
• none of these choices

45
Answer C

• The following are basic approaches to the coding
  process
• you can begin with a well developed coding scheme
• you can generate codes from your data

46

• 3. A _________________ is a document that
  describes the locations of variables and lists
  the assignments of codes to the attributes
  composing those variables.
• cross-case analysis
• codebook
• constant comparative method
• monitoring study

47
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.

48

• 4. The __________ is an average computed by
  summing the values of several observations and
  dividing by the number of observations.
• frequency
• mean
• median
• mode

49
Answer B

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

50

• 5. Which of the following are aimed at
  explanation
• multivariate analysis
• bivariate analysis
• univariate analysis
• both a and b

51
Answer D

• Multivariate analysis and bivariate analysis are
  aimed at explanation.

52

• 6. The multivariate techniques can serve as
  powerful tools for
• predicting behavior
• diagnosing social problems
• reacting to issues
• all of these choices

53
Answer B

• The multivariate techniques can serve as powerful
  tools for diagnosing social problems.