Methods in Behavioral Research TENTH EDITION

PAUL C. COZBY California State University, Fullerton

Higher Education

Boston Burr Ridge, IL Dubuque, IA New York San Francisco St. Louis Bangkok Bogota Caracas Kuala Lumpur Lisbon London Madrid Mexico City Milan Montreal New Delhi Santiago Seoul Singapore Sydney Taipei Toronto

Contents

Preface xlii

About the Author xvii

SCIENTIFIC UNDERSTANDING OF BEHAVIOR 1 Uses of Research Methods 2 The Scientific Approach 3 Goals of Science 7 Basic and Applied Research 10 Study Terms 14

Review Questions 14

Activity Questions 14

Answers 15

WHERE TO START 16 Hypotheses and Predictions 17 Who We Study: A Note on Terminology 18

Sources ofIdeas 18 Library Research 23 ' Anatomy of a Research Article 33

Study Terms 35

Review Questions 35

Activity Questions 36

ETHICAL RESEARCH 37 Milgram's Obedience Experiment 38 The Belmont Report 39

Assessment of Risks and Benefits 39 Informed Consent 42

The Importance of Debriefing 47

V I I

vüi Contents

Alternatives to Deception 47

Justice and the Selection of Participants 50 Researcher Commitments 50 Federal Regulations and the Institutional

Review Board 50 APA Ethics Code 53 Research With Human Participants 54 Ethics and Animal Research 56 Risks and Benefits Revisited 58 Misrepresentation: Fraud and Plagiarism 59 Study Terms 62

Review Questions 62

Activity Questions 63

Answers 64

82

MEASUREMENT CONCEPTS 90 Reliability of Measures 91 Construct Validity of Measures 96 Research on Personality and Individual Differences 99

Reactivity of Measures 100 Variables and Measurement Scales 100 Study Terms 104

Review Questions 104

Activity Questions 104

STUDYING BEHAVIOR 65 Variables 66

Operational Definitions of Variables 67 Relationships Between Variables 68 Nonexperimental Versus Experimental Methods 73

Independent and Dependent Variables 78 Causality 80 Choosing a Method: Advantages of Multiple Methods

Evaluating Research: Four Validities 85 Study Terms 87

Review Questions 87

Activity Questions 88

Answers 89

OBSERVATIONAL METHODS 106 Quantitative and Qualitative Approaches 107 Naturalistic Observation 108

Systematic Observation 112 Case Studies 115 Archival Research 116

Study Terms 119

Review Questions 119

Activity Questions 119

Answers 120

ASKING PEOPLE ABOUT THEMSELVES: SURVEY RESEARCH 121 Why Conduct Surveys? 122 Constructing Questions to Ask 124

Responses to Questions 127 Finalizing the Questionnaire 131 Administering Surveys 132

Survey Designs to Study Changes Over Time 135 Sampling From a Population 136 Sampling Techniques 138 Evaluating Samples 142

Reasons for Using Convenience Samples 143 Study Terms 145

Review Questions 145

Activity Questions 146

Answers 146

EXPERIMENTAL DESIGN 147 Confounding and Internal Validity 148 Basic Experiments 149

Assigning Participants to Experimental Conditions 153 Independent Groups Design 153 Repeated Measures Design 154 Matched Pairs Design 159

Study Terms 160

Review Questions 161

Activity Questions 161

X Contents

CONDUCTING EXPERIMENTS 162 Selecting Research Participants 163 Manipulating the Independent Variable 163 Measuring the Dependent Variable 169 Additional Controls 173 Additional Considerations 177 Analyzing and Interpreting Results 179 Communicating Research to Others 179 Study Terms 180

Review Questions 181

Activity Questions 181

Answers 182

COMPLEX EXPERIMENTAL DESIGNS 183 Increasing the Number of Levels of an Independent Variable 184 Increasing the Number of Independent Variables: Factorial Designs 185 Study Terms 198

Review Questions 198

Activity Questions 198

Answers 199

SINGLE CASE, QUASI-EXPERIMENTAL, AND DEVELOPMENTAL RESEARCH 200 Single Case Experimental Designs 201 Program Evaluation 205 Quasi-Experimental Designs 207 Developmental Research Designs 215 Study Terms 218

Review Questions 219

Activity Questions 219

UNDERSTANDING RESEARCH RESULTS: DESCRIPTION AND CORRELATION 222 Scales of Measurement: A Review 223 Analyzing the Results of Research Investigations 224

Frequency Distributions 226 Descriptive Statistics 228

Contents xi

Graphing Relationships 229

Correlation Coefficients: Describing the Strength of Relationships 230 Effect Size 235 Statistical Significance 236 Regression Equations 236

Multiple Correlation 237 Partial Correlation and the Third-Variable Problem 239

Structural Equation Modeling 240 Study Terms 241

Review Questions 242

Activity Questions 242

Answers 243

UNDERSTANDING RESEARCH RESULTS: STATISTICAL INFERENCE 244 Samples and Populations 245 Inferential Statistics 245

Null and Research Hypotheses 246 Probability and Sampling Distributions 247

Example: The t and FTests 250 Type I and Type II Errors 256

Choosing a Significance Level 259 Interpreting Nonsignificant Results 259 Choosing a Sample Size: Power Analysis 261

The Importance of Replications 262 Significance of a Pearson r Correlation Coefficient 262

Computer Analysis of Data 263 Selecting the Appropriate Statistical Test 265 Study Terms 266

Review Questions 266

Activity Questions 267

GENERALIZING RESULTS 268 Generalizing to Other Populations of Research Participants 269 Cultural Considerations 272 Generalizing to Other Experimenters 274 Pretests and Generalization 274 Generalizing from Laboratory Settings 275

xii Contents

The Importance of Replications 276 Evaluating Generalizations via Literature Reviews and Meta-Analysis 278 Using Research to Improve Lives 281 Study Terms 281

Review Questions 282

Activity Questions 282

APPENDIX A: WRITING RESEARCH REPORTS 283 Introduction 283 Writing Style 284 Organization of the Report 288

The Use of Headings 298

Citing and Referencing Sources 299 Abbreviations 307 Some Grammatical Considerations 309 Reporting Numbers and Statistics 312 Conclusion 313

Paper and Poster Presentations 313

Sample Paper 315

APPENDIX B: STATISTICAL TESTS 337 Descriptive Statistics 337 Statistical Significance Tests 340 Correlation and Effect Size 355

APPENDIX C: STATISTICAL TABLES 359 T a b l e d Random Number Table 361 Table C.2 Critical Values of Chi-Square 365 Table C.3 Critical Values off 366 Table C.4 Critical Values of F 367

Table C.5 Critical Values of r (Pearson product-moment correlation coefficient) 370

APPENDIX D: CONSTRUCTING A LATIN SQUARE 371

Glossary 3 73

References 381

Credits 393

Index 395