Research Methods S I X T H E D I T I O N Donald H. McBurney University of Pittsburgh Theresa L. White State University of New York Upstate Medical University Le Moyne College THOMSON WADSWORTH Australia Canada Mexico Singapore Spain United Kingdom United States
Contents 1 Psychology and Science 1 Ways of Knowing about Behavior l Nonempirical Methods 2 Empirical Methods 3 What Is Science? 5 Characteristics of Science 6 The Relation Between Science and Nonscience Working Assumptions of Science 9 The Reality of the World 9 Rationality 10 Regularity 10 Discoverability 11 Causality 11 The Goals of Science 12 12 16 The Discovery of Regularities The Development of Theories The Role of Theories 18 Hypotheses in Science 20 The Nature of Scientific Progress A Note on Psychology and Science Summary 22 Suggestions for Further Reading 23 A Case in Point 24 Reading Between the Lines 27 Exercises 29 2 Developing a Research Question 30 Choice of a Problem 30 The Literature Review 31 20 21
iv CONTENTS 3 Ethics in Research 50 4 Writing in Psychology 76 Using the Internet 32 Guidelines for Evaluating Information from the Internet 33 Search Engines 34 Government and Organizational Web Sites 34 Some Individual Web Sites for Psychology 35 Proprietary Web Sites 35 Email 37 Psychology Databases 38 An Extended Internet Search Example: Waist-Hip Ratio and Attractiveness 38 Inter-Library Loan 43 After You Locate the Important Articles 44 The Research Question 45 The Proposal 45 Summary 46 Exercises 47 The APA Ethics Code 59 Commentary on Responsibility 51 Commentary on Protection from Harm 52 Commentary on Informed Consent 54 Commentary on Privacy and Freedom from Coercion 54 Commentary on Deception 56 Commentary on Debriefing 57 Fraud in Research 59 Role of the Research Participant 60 Ethics and Animal Experimentation 61 Animal Rights and Animal Welfare 62 Speciesism? 62 The Case of the Silver Spring Monkeys 64 Nuts and Bolts 66 Summary 67 Suggestions for Further Reading 68 A Case in Point 68 Reading Between the Lines 73 Exercises 74 The Written Report 77 General 77 Avoiding Sexism and Ethnic Bias in Writing 79 The Parts of a Paper 80 Documenting Your Paper 83 Steps in the Publication Process 87
CONTENTS Oral Presentations 102 Poster Presentations 103 Nuts and Bolts 104 Summary 109 Suggestions for Further Reading 110 A Case in Point 110 Reading Between the Lines 115 Exercises 117 5 Variables 118 Types of Variables 119 Dependent and Independent Variables 119 Confounded Variables 120 Quantitative and Categorical Variables 121 Continuous and Discrete Variables 121 Measurement 122 What Is Measurement? 122 Types of Measurement Scales 123 Comparison of the Scales 125 Measurement and Statistics? 127 Reliability and Validity of Measurements 128 Variability and Error 128 Validity of Measurements 129 Nuts and Bolts 131 Summary 133 Suggestions for Further Reading 135 A Case in Point 135 Reading Between the Lines 135 Exercises 137 6 Tabular and Graphical Description of Data 140 Tables and Graphs of Frequency Data of One Variable 141 Frequency Tables 141 Frequency Distributions 142 Cumulative Frequency Distributions 144 Percentiles 144 Tables and Graphs That Show the Relationship Between Two Variables 145 Scattergrams 146 Tables with One Independent and One Dependent Variable 147 Graphs of Functions (Line Graphs) 148 Bar Graphs 148 Relation Between Frequency Distributions and Other Graphs 149 Time-Series Graphs 152
vi CONTENTS Indicating Variability of the Data in a Graph 153 Preparing Data for Analysis 154 Data Reduction 155 The Coding Guide 156 Checking for Invalid Data, Missing Data, and Outliers Proceeding with the Analysis 160 Nuts and Bolts 161 Summary 163 Suggestions for Further Reading 164 A Case in Point 164 Reading Between the Lines 165 Exercises 168 157 7 Validity 169 8 Control 189 Types of Validity 169 Internal Validity 170 Construct Validity 171 External Validity 172 Statistical Validity 173 Threats to Validity 173 Threats to Internal Validity 173 Threats to Construct Validity 176 Threats to External Validity 177 Threats to Statistical Validity 179 Summary Note on Validity 179 Nuts and Bolts 179 Summary 182 Suggestions for Further Reading 183 A Case in Point 183 Reading Between the Lines 185 Exercises 186 The Concept of Control 189 Control Provides a Standard of Comparison 190 Control Reduces Variability 191 General Strategies 192 Control in the Laboratory 192 The Research Setting as a Preparation 193 Instrumentation of the Response as Control 194 Specific Strategies 194 Subject as Own Control (Within-Subjects Control) 194 Random Assignment 196 Matching 198
CONTENTS vii Building Nuisance Variables into the Experiment 199 Statistical Control 201 Replication, Replication 203 Experimental Design as Problem Solving 205 The Elegant Experiment 205 How to Use the Rest of This Book 206 Nuts and Bolts 206 Summary 209 Suggestion for Further Reading 211 A Case in Point 211 Reading Between the Lines 212 Exercise 213 9 Nonexperimental Research, Part 1: Observational, Archival, and Case-Study Research 214 The Hermeneutic Approach 216 Observational Research 216 Naturalistic Observation 217 Participant-Observer Research 221 Archival Research 223 Case Studies 224 Theory Development and Testing in Observational and Archival Research 225 Nuts and Bolts 227 Summary 231 Suggestions for Further Reading 232 A Case in Point 232 Reading Between the Lines 235 Exercises 237 10 Nonexperimental Research, Part 2: Survey Research 238 How a Questionnaire Is Designed 238 Determine the Purpose of the Questionnaire 239 " Determine the Types of Questions 239 Write the Items 240 Determine How the Data Will Be Analyzed 244 Administering the Questionnaire 244 Determine the Method of Administration 244 The Problem of Response Rate 246 Sampling 247 Types of Samples 247 Probability Samples and Random Selection 248 Summary of Sampling Procedures 253 Nuts and Bolts 254 Summary 256
viii CONTENTS Suggestions for Further Reading 256 A Case in Point 257 Reading Between the Lines 259 Exercises 260 11 True Experiments, Part 1: Single-Factor Designs 265 True Experiments 265 Factors, Levels, Conditions, and Treatments 266 Some Designs to Avoid 266 The One-Group Posttest-Only Design 267 The Posttest-Only Design with Nonequivalent Control Groups 267 The One-Group Pretest-Posttest Design 268 The Basic Elements of a Valid Experimental Design 269 Within-Subjects Designs 270 Controlling for Order and Sequence Effects 270 Two Conditions, Tested Within Subjects 274 Multiple Conditions, Tested Within Subjects 275 Between-Subjects Designs 277 Two Conditions, Tested Between Subjects 277 Multiple Conditions, Tested Between Subjects 277 Summary 279 Suggestions for Further Reading 280 A Case in Point 280 Reading Between the Lines 282 Exercises 284 12 True Experiments, Part 2: Factorial Designs 286 A Simple Factorial Design 288 Main Effects 289 Interactions 290 Interactions When There Is No Main Effect 291 Types of Interactions 294 Within-Subjects, Between-Subjects, and Mixed Designs 294 Advantages of Within-Subjects Designs 299 Control in Within-Subjects Factorial Experiments 299 Some Representative Factorial Designs 300 Factorial, Within-Subjects 300 Factorial, Between-Subjects 301 A Mixed Factorial Design 301 Summary 302 Suggestions for Further Reading 303 A Case in Point 303
CONTENTS ix Reading Between the Lines 304 Exercises 306 13 Single-Participant Experiments 309 14 Quasi Experiments 330 Advantages of the Single-Participant Approach 310 Focusing on Individual Performance 311 ^ Focusing on Big Effects 312 Avoiding Ethical and Practical Problems 313 Flexibility in Design 313 Disadvantages of the Single-Participant Approach 313 Basic Control Strategies in Single-Participant Research 314 Obtaining a Stable Baseline 314 Comparison (AB Design) 315 Withdrawal of Treatment (ABA Designs) 315 Repeating Treatments (ABAB Designs) 315 Changing Only One Variable at a Time 318 Using Multiple Baselines 319 Employing a Changing Criterion 321 Two Examples from Psychophysics 321 Summary 324 Suggestions for Further Reading 325 A Case in Point 326 Reading Between the Lines 326 Exercises 328 The Principal Difference Between Quasi Experiments and True Experiments 330 Other Features of Quasi Experiments 332 Which Is the Best Research Method? 332 Nonequivalent Control Group Designs 333 Mixed Factorial Design with One Nonmanipulated Variable 336 Designs Without Control Groups 336 Interrupted Time-Series Designs 337 Repeated-Treatment Designs 340 Designs to Test Developmental Changes 341 Program Evaluation 345 Sources of Resistance to Program Evaluations 346 Steps in Planning an Evaluation 347 Two Examples of Program Evaluation 349 Nuts and Bolts 350 Summary 353. Suggestions for Further Reading 354 A Case in Point 355
x CONTENTS Reading Between the Lines 357 Exercises 359 Epilogue Biases and Limitations of Experimental Psychology 361 Biases 362 Science as Conservative 362 Science as Liberal 364 Limitations of Science 365 Essential Limitations 366 Practical Limitations 368 The Responsibilities of the Scientist 368 Summary Note on Biases and Limitations of Science 369 Summary 370 Suggestions for Further Reading 371 Reading Between the Lines 371 Exercises 372 Appendix A Review of Statistics 373 Some Basic Terms 373 Descriptive Statistics 374 Measures of Central Tendency 374 Measures of Variability 377 Correlation and Regression 380 Inferential Statistics 385 Sampling Distributions 385 Testing Hypotheses 387 Dealing with Uncertainty in Hypothesis Testing 389 The Significance of Significance 392 Effect Size 393 Analysis of Variance 394 Exercises 401 Appendix B Random-Number Table 406 Appendix C Population Data Set 408 Appendix D Suggested Answers to "Reading Between the Lines" 410 Appendix E Key for Identifying Appropriate Graphs and Statistics 417 References 421 Indexes 429