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

by Marjorie A. Pett

• ISBN13: 9780761919506
• ISBN10: 0761919503
• Format: Paperback
• Copyright: 2003-03-21
• Publisher: SAGE Publications, Inc

Summary

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.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.

Table of Contents

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