An approachable, coherent, and important text, Research in Psychology: Methods and Design, 8th Edition continues to provide its readers with a clear, concise look at psychological science, experimental methods, and correlational research in this newly updated version. Rounded out with helpful learning aids, step-by-step instructions, and detailed examples of real research studies makes the material easy to read and student-friendly.

Summary of Research Examples xv

Preface xvii

1 Scientific Thinking in Psychology 1

Why Take This Course? 2

Ways of Knowing 5

Authority 5

Use of Reason 5

Empiricism 6

The Ways of Knowing and Science 8

Science as a Way of Knowing 9

Science Assumes Determinism 9

Science Makes Systematic Observations 10

Science Produces Public Knowledge 10

Box 1.1: ORIGINS—A Taste of Introspection 11

Science Produces Data-Based Conclusions 12

Science Produces Tentative Conclusions 13

Science Asks Answerable Questions 14

Science Develops Theories That Can Be Falsified 14

Psychological Science and Pseudoscience 15

Recognizing Pseudoscience 16

Associates with True Science 17

Box 1.2: CLASSIC STUDIES—Falsifying Phrenology 18

Relies on Anecdotal Evidence 19

Sidesteps the Falsification Requirement 20

Reduce Complex Phenomena to Overly Simplistic Concepts 21

The Goals of Research in Psychology 21

Describe 21

Predict 22

Explain 22

Apply 22

A Passion for Research in Psychology 23

Eleanor Gibson (1910–2002) 24

B. F. Skinner (1904–1990) 25

2 Ethics in Psychological Research 30

Box 2.1: CLASSIC STUDIES—Infants at Risk 31

Developing a Code of Ethics for Psychological Science 32

Ethical Guidelines for Research with Humans 35

Weighing Benefits and Costs: The Role of the IRB 35

Informed Consent and Deception in Research 38

Box 2.2: ETHICS—Historical Problems with Informed Consent 39

Informed Consent and Special Populations 41

Use of Deception 42

Treating Participants Well 43

Research Ethics and the Internet 46

Ethical Guidelines for Research with Animals 47

Animal Rights 48

Box 2.3: ORIGINS—Antivivisection and the APA 48

Using Animals in Psychological Research 50

The APA Code for Animal Research 52

Justifying the Study 52

Caring for the Animals 52

Using Animals for Educational Purposes 53

Scientific Fraud 53

Data Falsification 54

3 Developing Ideas for Research in Psychology 60

Varieties of Psychological Research 61

The Goals: Basic versus Applied Research 61

The Setting: Laboratory versus Field Research 63

Research Example 1—Combining Laboratory and Field Studies 64

The Data: Quantitative versus Qualitative Research 66

Asking Empirical Questions 67

Operational Definitions 67

Developing Research from Observations of Behavior and Serendipity 69

Box 3.1: ORIGINS—Serendipity and Edge Detectors 70

Developing Research from Theory 70

The Nature of Theory 71

The Relationship between Theory and Research 72

Attributes of Good Theories 74

Falsification 74

Box 3.2: CLASSIC STUDIES—Falsification and Der Kluge Hans 75

Parsimony 77

Common Misunderstandings about Theory 78

Developing Research from Other Research 78

Research Teams and the “What’s Next?” Question 79

Research Example 2 – “What’s Next?” 80

Replication 82

Box 3.3: ETHICS—Questionable Research Practices and Replication Remedies 83

Creative Thinking in Science 84

Reviewing the Literature 86

Computerized Database Searches 86

Search Tips 87

Search Results 88

4 Sampling, Measurement, and Hypothesis Testing 93

Who to Measure—Sampling Procedures 94

Probability Sampling 94

Random Sampling 94

Stratified Sampling 95

Cluster Sampling 95

Nonprobability Sampling 96

What to Measure—Varieties of Behavior 96

Developing Measures from Constructs 97

Research Example 3—Testing Constructs Using Habituation 98

Research Example 4—Testing Constructs Using Reaction Time 99

Box 4.1: ORIGINS—Reaction Time: From Mental Chronometry to Mental Rotation 100

Evaluating Measures 101

Reliability 101

Validity 103

Research Example 5—Construct Validity 104

Reliability and Validity 105

Scales of Measurement 105

Nominal Scales 106

Ordinal Scales 107

Interval Scales 108

Box 4.2: CLASSIC STUDIES—Measuring Somatotypes on an Interval Scale: Hoping for 4-4-4 108

Ratio Scales 109

Statistical Analysis 110

Descriptive and Inferential Statistics 111

Descriptive Statistics 111

Box 4.3: ETHICS—Statistics that Mislead 116

Inferential Statistics 117

Null Hypothesis Significance Testing 118

Type I and Type II Errors 120

Interpreting Failures to Reject H0 121

Beyond Null Hypothesis Significance Testing 122

Effect Size 123

Confidence Intervals 124

Power 125

5 Introduction to Experimental Research 129

Essential Features of Experimental Research 130

Box 5.1: ORIGINS—John Stuart Mill and the Rules of Inductive Logic 131

Establishing Independent Variables 132

Varieties of Manipulated Independent Variables 132

Control Groups 133

Research Example 6—Experimental and Control Groups 133

Controlling Extraneous Variables 134

Measuring Dependent Variables 136

Subject Variables 137

Research Example 7—Using Subject Variables 138

Drawing Conclusions When Using Subject Variables 140

Box 5.2: CLASSIC STUDIES—Bobo Dolls and Aggression 141

The Validity of Experimental Research 143

Statistical Conclusion Validity 143

Construct Validity 144

External Validity 144

Other Populations 144

Box 5.3: ETHICS—Recruiting Participants: Everyone’s in the Pool 145

Other Environments 147

Other Times 148

A Note of Caution about External Validity 148

Internal Validity 148

Threats to Internal Validity 149

Studies Extending Over Time 149

History and Maturation 150

Regression to the Mean 151

Testing and Instrumentation 152

Participant Problems 152

Subject Selection Effects 152

Attrition 153

A Final Note on Internal Validity, Confounding, and External Validity 154

6 Methodological Control in Experimental Research 159

Between-Subjects Designs 160

Creating Equivalent Groups 161

Random Assignment 161

Matching 163

Within-Subjects Designs 167

Controlling Order Effects 169

Testing Once per Condition 170

Complete Counterbalancing 170

Partial Counterbalancing 170

Testing More than Once per Condition 171

Reverse Counterbalancing 172

Block Randomization 172

Research Example 8—Counterbalancing with Block

Randomization 173

Methodological Control in Developmental Research 174

Box 6.1: CLASSIC STUDIES—The Record for Repeated Measures 176

Controlling for the Effects of Bias 177

Experimenter Bias 177

Controlling for Experimenter Bias 178

Research Example 9—Using a Double Blind Procedure 179

Participant Bias 180

Box 6.2: ORIGINS—Productivity at Western Electric 181

Research Example 10—Demand Characteristics 182

Controlling for Participant Bias 183

Box 6.3: ETHICS—Research Participants Have Responsibilities Too 185

7 Experimental Design I: Single-Factor Designs 189

Single Factor—Two Levels 190

Between-Subjects, Single-Factor Designs 191

Research Example 11—Two-Level Independent Groups Design 192

Research Example 12— Two-Level Matched Groups Design 193

Research Example 13— Two-Level Ex Post Facto Design 194

Within-Subjects, Single-Factor Designs 194

Box 7.1: CLASSIC STUDIES—Psychology’s Most Widely Replicated Finding? 195

Research Example 14—Two-Level Repeated Measures Design 196

Single Factor—More Than Two Levels 198

Between-Subjects, Multilevel Designs 199

Research Example 15—Multilevel Independent Groups Design 199

Within-Subjects, Multilevel Designs 201

Research Example 16—Multilevel Repeated Measures Design 201

Analyzing Data from Single-Factor Designs 202

Presenting the Data 202

Types of Graphs 203

Box 7.2: ORIGINS—The Ebbinghaus Forgetting Curve 204

Analyzing the Data 206

Statistics for Single-Factor, Two-Level Designs 206

Statistics for Single-Factor, Two-Level Designs 207

Special-Purpose Control Group Designs 209

Placebo Control Group Designs 209

Wait List Control Group Designs 210

Box 7.3: ETHICS—Who’s in the Control Group? 210

Research Example 17—Using Both Placebo

and Wait List Control Groups 212

Yoked Control Group Designs 213

Research Example 18—A Yoked Control Group 213

8 Experimental Design II: Factorial Designs 219

Essentials of Factorial Designs 220

Identifying Factorial Designs 220

Outcomes—Main Effects and Interactions 221

Main Effects 221

Research Example 19—Main Effects 223

Interactions 225

Research Example 20—An Interaction with No Main Effects 226

Interactions Sometimes Trump Main Effects 228

Combinations of Main Effects and Interactions 229

Creating Graphs for the Results of Factorial Designs 232

Box 8.1: CLASSIC STUDIES—To Sleep, Perchance to Recall 235

Varieties of Factorial Designs 237

Mixed Factorial Designs 238

Research Example 21—A Mixed Factorial with Counterbalancing 239

Research Example 22—A Mixed Factorial without Counterbalancing 240

Factorials with Subject and Manipulated Variables: P × E Designs 241

Research Example 23—A Factorial Design with a P × E Interaction 244

Research Example 24—A Mixed P × E Factorial with Two Main Effects 245

Recruiting Participants for Factorial Designs 246

Box 8.2: ETHICS—On Being a Competent and Ethical Researcher 248

Analyzing Data from Factorial Designs 249

Box 8.3: ORIGINS—Factorials Down on the Farm 250

9 Non-Experimental Design I: Survey Methods 255

Survey Research 256

Box 9.1: ORIGINS—Creating the “Questionary” 256

Sampling Issues in Survey Research 257

Surveys versus Psychological Assessment 259

Creating an Effective Survey 259

Types of Survey Questions or Statements 259

Assessing Memory and Knowledge 262

Adding Demographic Information 262

A Key Problem: Survey Wording 263

Collecting Survey Data 266

In-Person Interviews 266

Mailed Written Surveys 267

Phone Surveys 268

Online Surveys 268

Ethical Considerations 269

Box 9.2: ETHICS—Using and Abusing Surveys 269

Research Example 25—A Survey of College Students’ Study Strategies 270

Analyzing Data from Non-Experimental Methods 272

Correlation: Describing Relationships 272

Scatterplots 273

Correlation Coefficients 275

Coefficient of Determination 276

Be Aware of Outliers 277

Regression: Making Predictions 277

Research Example 26 – Regression and Multiple Regression 280

Interpreting Correlational Results 282

Directionality 282

Research Example 27—Correlations and Directionality 283

Third Variables 284

Combining Non-Experimental and Experimental Methods 286

Research Example 28—Combining Methods 286

10 Non-Experimental Design II: Observational and Archival Methods 291

Observational Research 292

Varieties of Observational Research 292

Naturalistic Observation 293

Participant Observation 294

Box 10.1: CLASSIC STUDIES—When Prophecy Fails 294

Challenges Facing Observational Methods 295

Absence of Control 295

Observer Bias 296

Participant Reactivity 297

Ethics 298

Box 10.2: ETHICS—A Matter of Privacy 298

Research Example 29—A Naturalistic Observation 299

Research Example 30—A Covert Participant Observation 301

Analyzing Qualitative Data from Non-Experimental Designs 302

Archival Research 303

Archival Data 304

Research Example 31—A Non-Experimental Design Using Archival Data 305

Analyzing Archival Data 307

Meta-Analysis—A Special Case of Archival Research 308

Research Example 32—Meta-analysis and Psychology’s First Registered Replication Report (RRR) 309

11 Quasi-Experimental Designs and Applied Research 313

Beyond the Laboratory 314

Research Example 33—Applied Research 315

Applied Psychology in Historical Context 316

Box 11.1: CLASSIC STUDIES—The Hollingworth’s, Applied Psychology, and Coca-Cola 318

Design Problems in Applied Research 319

Quasi-Experimental Designs 320

Nonequivalent Control Group Designs 320

Outcomes 321

Regression to the Mean and Matching 322

Research Example 34—A Nonequivalent Control Group Design 325

Research Example 35—A Nonequivalent Control Group Design Without Pretests 327

Interrupted Time Series Designs 327

Outcomes 328

Research Example 36—An Interrupted Time Series Design 329

Variations on the Basic Time Series Design 330

Program Evaluation 332

Box 11.2: ORIGINS—Reforms as Experiments 332

Planning for Programs—Needs Analysis 333

Research Example 37—Assessing Need in Program Evaluation 334

Monitoring Programs—Formative Evaluation 335

Evaluating Outcomes—Summative Evaluation 336

Weighing Costs—Cost-Effectiveness Analysis 337

A Note on Qualitative Data Analysis 338

Box 11.3: ETHICS—Evaluation Research and Ethics 338

12 Small N Designs 343

Research in Psychology Began with Small N 344

Box 12.1: ORIGINS—Cats in Puzzle Boxes 346

Reasons for Small N Designs 347

Occasional Misleading Results from Statistical Summaries of Grouped Data 347

Practical and Philosophical Problems with Large N Designs 349

The Experimental Analysis of Behavior 350

Applied Behavior Analysis 353

Box 12.2: ETHICS—Controlling Human Behavior 353

Small N Designs in Applied Behavior Analysis 355

Elements of Single-Subject Designs 355

Withdrawal Designs 356

Research Example 38—An A–B–A–B Design 357

Multiple Baseline Designs 357

Research Example 39—A Multiple Baseline Design 360

Changing Criterion Designs 360

Research Example 40—A Changing Criterion Design 361

Alternating Treatments Designs 363

Research Example 41—An Alternating Treatments Design 363

Evaluating Single-Subject Designs 365

Case Study Designs 367

Research Example 42—A Case Study 368

Box 12.3: CLASSIC STUDIES—The Mind of a Mnemonist 370

Evaluating Case Studies 371

Epilogue: What I Learned in My Research Methods Course 376

Appendix A Communicating the Results of Research in Psychology 379

Research Reports and APA-Style 379

General Guidelines 380

Writing Style 380

Using Numbers 380

Reducing Bias in Language 382

Avoiding Plagiarism 383

Main Sections of the Research Report 384

Presentations and Posters 395

Tips for Presenting a Paper 395

Tips for Presenting a Poster 395

Appendix B Answers to Selected End-of-Chapter Applications Exercises 399

Chapter 1. Scientific Thinking in Psychology 399

Chapter 2. Ethics in Psychological Research 400

Chapter 3. Developing Ideas for Research in Psychology 400

Chapter 4. Sampling, Measurement, and Hypothesis Testing 401

Chapter 5. Introduction to Experimental Research 402

Chapter 6. Methodological Control in Experimental Research 403

Chapter 7. Experimental Design I: Single-Factor Designs 405

Chapter 8. Experimental Design II: Factorial Designs 408

Chapter 9. Non-Experimental Design I: Survey Methods 410

Chapter 10. Non-Experimental Design II: Observational and Archival Methods 411

Chapter 11. Quasi-Experimental Designs and Applied Research 411

Chapter 12. Small N Designs 413

Appendix A. Communicating the Results of Research in Psychology 414

Glossary 416

References 430

Index 451