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Making Sense of Factor Analysis
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Making Sense of Factor Analysis
The Use of Factor Analysis for Instrument Development in Health Care Research



April 2003 | 368 pages | SAGE Publications, Inc

Many health care practitioners and researchers are aware of the need to employ factor analysis in order to develop more sensitive instruments for data collection. Unfortunately, factor analysis is not a unidimensional approach that is easily understood by even the most experienced of researchers.

Making Sense of Factor Analysis: The Use of Factor Analysis for Instrument Development in Health Care Research presents a straightforward explanation of the complex statistical procedures involved in factor analysis. Authors Marjorie A. Pett, Nancy M. Lackey, and John J. Sullivan provide a step-by-step approach to analyzing data using statistical computer packages like SPSS and SAS. Emphasizing the interrelationship between factor analysis and test construction, the authors examine numerous practical and theoretical decisions that must be made to efficiently run and accurately interpret the outcomes of these sophisticated computer programs.

This accessible volume will help both novice and experienced health care professionals to

  • Increase their knowledge of the use of factor analysis in health care research
  • Understand journal articles that report the use of factor analysis in test construction and instrument development
  • Create new data collection instruments
  • Examine the reliability and structure of existing health care instruments
  • Interpret and report computer-generated output from a factor analysis run

Making Sense of Factor Analysis: The Use of Factor Analysis for Instrument Development in Health Care Research offers a practical method for developing tests, validating instruments, and reporting outcomes through the use of factor analysis. To facilitate learning, the authors provide concrete testing examples, three appendices of additional information, and a glossary of key terms. Ideal for graduate level nursing students, this book is also an invaluable resource for health care researchers.


 
1. An Overview of Factor Analysis
Characteristics of Factor Analysis

 
Exploratory Vs. Confirmatory Factor Analysis

 
Assumptions of Exploratory Factor Analysis

 
Historical Developments of Factor Analysis

 
Uses of Factor Analysis in Health Care Research

 
Decision-Making Process in Exploratory Factor Analysis

 
 
2. Designing and Testing the Instrument
Types of Measurement and Frameworks

 
The Use of Latent Variables in Instrument Development

 
Identifying Empirical Indicators of Latent Variables

 
Using Qualitative Research Methods to Identify Empirical Indicators

 
Additional Qualitative Approaches to Identifying Empirical Indicators

 
Development of the Instrument

 
Scoring the Instrument

 
Pilot Testing the Instrument

 
Determining the Number of Subjects

 
 
3. Assessing the Characteristics of Matrices
Characteristics and Types of Matrices

 
Tests of Matrices

 
Review of the Process

 
 
4. Extracting the Initial Factors
Evaluating the Correlation Matrix

 
Sources of Variance in Factor Analysis Models

 
Determining the Factor Extraction Method

 
Selecting the Number of Factors to Retain

 
Comparing the Two-Factor Solution Using PCA and PAF

 
 
5. Rotating the Factors
Achieving a Simple Structure

 
Types of Rotations

 
Mapping Factors in Geometric Space

 
Orthogonal Rotations

 
Oblique Rotations

 
Comparing the Orthogonal and Oblique Solutions

 
Advantages and Disadvantages of the Oblique Solution

 
Choosing Between Orthogonal and Oblique Rotations

 
Summary of the Process of Rotations

 
 
6. Evaluating and Refining the Factors
Evaluating and Refining the Factors

 
Assessing the Reliability of an Instrument

 
Evaluating the Internal Consistency of an Instrument

 
Estimating the Effects on Reliability of Increasing or Decreasing Items

 
Cronbach's Coefficient Alpha

 
Assessing Reliability Using Cronbach's Alpha: A Computer Example

 
Two Additional Reliability Estimates: Temporal Stability and Equivalence

 
 
7. Interpreting Factors and Generating Factor Scores
Interpreting the Factors

 
Naming the Factors

 
Interpreting and Naming the Four Factors on the CGTS Scale

 
Determining Composite Factor Scores

 
 
8. Reporting and Replicating the Results
When to Report the Results

 
What to Include in the Report

 
An Exemplar of a Published Report

 
Replicating the Factors in Other Studies

 
Conclusions

 
 
Appendix A: Concerns About Genetic Testing Scale
 
Appendix B: SAS Commands and Generate Output
 
Appendix C: Output for 20-item CGTS Scale
 
Appendix D: Tables for the Chi-Square and Normal Distributions
 
Appendix E: Unraveling the Mystery of Principal Component Extraction
 
References
 
Index
 
About the Authors

an excellent and very useful book for anyone embarking on factor analysis

Ms Janas Harrington
Dept Epidemiology & Public Health, University College Cork (NUI)
February 10, 2010

Absolutely brilliant - descriptive, easily read and motivating. Good examples from health and particularly a good description of different rotations, why we do FA, explains the print outs. All my colleagues want to borrow it too!
Good for students doing questionnaires with a large number of participants.

Dr Sue Hacking
Nursing , Central Lancashire University
November 12, 2009
Key features
  • Authors use genetic testing example throughout book

This helps give readers a concrete example to use for applying the more difficult concepts

  • Authors provide step-by-step descriptions of the approach to analyzing data using statistical computer packages

This provides readers with easy to understand information about a crucial component of FA

  • Authors provide three appendices and a glossary

This information provides readers with additional source materials

Sample Materials & Chapters

Excel Data Set

SPSS Data Set


This title is also available on SAGE Research Methods, the ultimate digital methods library. If your library doesn’t have access, ask your librarian to start a trial.