The Psychologist as Detective An Introduction to Conducting
Research in Psychology
Randolph A. Smith Lamar University
Stephen F. Davis Morningside College
Upper Saddle River London Singapore Toronto Tokyo Sydney Hong Kong Mexico City
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Library of Congress Cataloging-in-Publication Data
Smith, Randolph A. The psychologist as detective : an introduction to conducting research in psychology / Randolph A. Smith,
Stephen F. Davis. — 5th ed. p. cm.
Includes bibliographical references and index. ISBN 978-0-205-68740-4 (alk. paper)
1. Psychology–Research–Textbooks. 2. Psychology–Research–Methodology–Textbooks. 3. Psychology, Experimental–Textbooks. I. Davis, Stephen F. II. Title.
BF76.5.S54 2010 150.72—dc22 2009001784
10 9 8 7 6 5 4 3 2 1
ISBN 10: 0-205-68740-7 ISBN 13: 978-0-205-68740-4
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We dedicate the fifth edition of this text to the loving memory of Corliss Smith (1952–2009). Her support made this book possible. Please consider a donation to the ALS Association
(www.alsa.org) to fight this cruel disease.
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C H A P T E R 1 Psychological Research and the Research Methods Course 1 How Psychologists Acquire Knowledge 3 The Research Process 4
Finding a Problem 5 Reviewing the Literature 5 Theoretical Considerations 5 Hypothesis 6 Research Plan 6 Conducting the Research Project 6 Analysis of Research Findings 6 Decisions in Terms of Past Research and Theory 7 Preparing the Research Report 7 Sharing Your Results: Presentation and Publication 7 Finding a New Problem 11
Why Is the Research Methods Course Important? 11 Review Summary 12 Check Your Progress 13 Key Terms 13 Looking Ahead 13
C H A P T E R 2 Developing a Good Research Idea and Conducting an Ethical Project 14 The Research Idea 14
Characteristics of Good Research Ideas 14 Sources of Research Ideas 16
Developing a Research Question 19 Surveying the Psychological Literature 20
Review Summary 28 Check Your Progress 28
The Need for Ethical Principles 29
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APA Principles in the Conduct of Research with Humans 32 Is Deception in Research Necessary? 34 Informed Consent 34 Participants at Risk and Participants at Minimal Risk 36 Vulnerable Populations 36 The Debriefing Session 37
The Ethical Use of Animals in Psychological Research 38 The Institutional Review Board 39 The Experimenter’s Responsibility 40 The Participants’ Responsibility 40 The Researcher’s Ethical Obligations Once the Research Is Completed 42
Plagiarism 42 Fabrication of Data 43 Lying with Statistics 45 Citing Your References Correctly 45 Review Summary 47 Check Your Progress 47 Key Terms 48 Looking Ahead 48
C H A P T E R 3 Qualitative Research Methods 49 General Overview 50
Characteristics of Qualitative Research 50 Data Analysis 51
Selected Examples of Qualitative Research Methods 52 Naturalistic Observation 52 Ethnographic Inquiry 52 Focus Groups 53 Case Studies 54 Grounded Theory 54 Participatory Action Research 56 Review Summary 57 Check Your Progress 57 Key Terms 58 Looking Ahead 58
C H A P T E R 4 Nonexperimental Methods: Descriptive Methods, Correlational Studies, Ex Post Facto Studies, Surveys and Questionnaires, Sampling, and Basic Research Strategies 59 Descriptive Methods 59
Archival and Previously Recorded Sources of Data 59
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Naturalistic Observation 61 Choosing Behaviors and Recording Techniques 63
Correlational Studies 66 The Nature of Correlations 66 Correlational Research 67 Review Summary 68 Check Your Progress 69
Ex Post Facto Studies 69
Surveys, Questionnaires, Tests, and Inventories 70 Surveys and Questionnaires 70 Tests and Inventories 76
Sampling Considerations and Basic Research Strategies 79
Sampling 79 Basic Research Strategies 81 Review Summary 83 Check Your Progress 84 Key Terms 85 Looking Ahead 85
C H A P T E R 5 Using the Scientific Method in Psychology 86 Components of the Scientific Method 86
Objectivity 86 Confirmation of Findings 87 Self-Correction 87 Control 87
The Psychological Experiment 88 Independent Variable 88 Dependent Variable 89 Extraneous Variables 89
Establishing Cause-and-Effect Relations 89
Formulating the Research Hypothesis 91
Characteristics of the Research Hypothesis 92 Types of Statements 92 Types of Reasoning 94 A New View of Hypothesis Testing 95 Directional Versus Nondirectional Research Hypotheses 96 Review Summary 97 Check Your Progress 98 Key Terms 99
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C H A P T E R 6 Conducting a Good Experiment I: Variables and Control 100 The Nature of Variables 100 Operationally Defining Variables 101 Independent Variables 102
Types of IVs 102
Extraneous Variables (Confounders) 103 Dependent Variables 105
Selecting the DV 106 Recording or Measuring the DV 106 Recording More Than One DV 107 Characteristics of a Good DV 108
Nuisance Variables 109 Review Summary 111 Check Your Progress 112
Controlling Extraneous Variables 112 Basic Control Techniques 113 Review Summary 124 Check Your Progress 124 Key Terms 125 Looking Ahead 125
C H A P T E R 7 Conducting a Good Experiment II: Final Considerations, Unanticipated Influences, and Cross-Cultural Issues 126 Participants 126
Types of Participants 126 Number of Participants 128
Apparatus 129 IV Presentation 129 DV Recording 131 Review Summary 131 Check Your Progress 132
The Experimenter as an Extraneous Variable 132 Experimenter Characteristics 133 Experimenter Expectancies 133 Controlling Experimenter Effects 134
Participant Perceptions as Extraneous Variables 135 Demand Characteristics and Good Participants 135 Response Bias 137 Controlling Participant Effects 138
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Review Summary 140 Check Your Progress 140
The Interface Between Research and Culture 141 Culture, Knowledge, and Truth 142 The Effect of Culture on Research 143 Methodology and Analysis Issues 143 Review Summary 145 Check Your Progress 146 Key Terms 146 Looking Ahead 146
C H A P T E R 8 Internal and External Validity 147 Internal Validity: Evaluating Your Experiment from the Inside 147
Threats to Internal Validity 147 Protecting Internal Validity 155 Review Summary 155 Check Your Progress 156
External Validity: Generalizing Your Experiment to the Outside 157 Threats to External Validity (Based on Methods) 159 Threats to External Validity (Based on Our Participants) 162 The Devil’s Advocate: Is External Validity Always Necessary? 167 Review Summary 169 Check Your Progress 170 Key Terms 170 Looking Ahead 170
C H A P T E R 9 Using Statistics to Answer Questions 171 Descriptive Statistics 171
Scales of Measurement 172 Measures of Central Tendency 173 Graphing Your Results 176 Calculating and Computing Statistics 181 Measures of Variability 182 Review Summary 187 Check Your Progress 187
Correlation 188 The Pearson Product–Moment Correlation Coefficient 191
Inferential Statistics 192 What Is Significant? 192 The t Test 193 One-Tail Versus Two-Tail Tests of Significance 196 The Logic of Significance Testing 196 When Statistics Go Astray: Type I and Type II Errors 199
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Effect Size 200 Review Summary 201 Check Your Progress 201 Key Terms 202 Looking Ahead 202
C H A P T E R 10 Designing, Conducting, Analyzing, and Interpreting Experiments with Two Groups 203 Experimental Design: The Basic Building Blocks 203
The Two-Group Design 204 Review Summary 213 Check Your Progress 214 Comparing Two-Group Designs 214 Variations on the Two-Group Design 218 Review Summary 220 Check Your Progress 220
Statistical Analysis: What Do Your Data Show? 220 The Relation Between Experimental Design and Statistics 220 Analyzing Two-Group Designs 221 Calculating Your Statistics 221
Interpretation: Making Sense of Your Statistics 222 Interpreting Computer Statistical Output 222
The Continuing Research Problem 228 Review Summary 229 Check Your Progress 230 Key Terms 230 Looking Ahead 230
C H A P T E R 11 Designing, Conducting, Analyzing, and Interpreting Experiments with More Than Two Groups 231 Experimental Design: Adding to the Basic Building Block 231
The Multiple-Group Design 232 Comparing the Multiple-Group and Two-Group Designs 238 Comparing Multiple-Group Designs 240 Variations on the Multiple-Group Design 241 Review Summary 242 Check Your Progress 243
Statistical Analysis: What Do Your Data Show? 243 Analyzing Multiple-Group Designs 243 Planning Your Experiment 244 Rationale of ANOVA 245
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Interpretation: Making Sense of Your Statistics 247 Interpreting Computer Statistical Output 248
The Continuing Research Problem 256 Review Summary 257 Check Your Progress 257 Key Terms 258 Looking Ahead 258
C H A P T E R 12 Designing, Conducting, Analyzing, and Interpreting Experiments with Multiple Independent Variables 259 Experimental Design: Doubling the Basic Building Block 259
The Factorial Design 260 Review Summary 272 Check Your Progress 273 Comparing the Factorial Design to Two-Group and Multiple-Group Designs 273 Choosing a Factorial Design 276 Variations on Factorial Designs 277 Review Summary 282 Check Your Progress 282
Statistical Analysis: What Do Your Data Show? 283 Naming Factorial Designs 283 Planning the Statistical Analysis 284 Rationale of Factorial ANOVA 284 Understanding Interactions 285
Interpretation: Making Sense of Your Statistics 287 Interpreting Computer Statistical Output 287 A Final Note 296
The Continuing Research Problem 296 Review Summary 297 Check Your Progress 298 Key Terms 299 Looking Ahead 299
C H A P T E R 13 Alternative Research Designs 300 Protecting Internal Validity Revisited 300
Examining Your Experiment from the Inside 300 Protecting Internal Validity with Research Designs 303 Conclusion 307 Review Summary 307 Check Your Progress 308
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Single-Case Experimental Designs 308 History of Single-Case Experimental Designs 310 Uses of Single-Case Experimental Designs 310 General Procedures of Single-Case Experimental Designs 311 Statistics and Single-Case Experimental Designs 313 Representative Single-Case Experimental Designs 314 Review Summary 320 Check Your Progress 321
Quasi-Experimental Designs 321 History of Quasi-Experimental Designs 322 Uses of Quasi-Experimental Designs 323 Representative Quasi-Experimental Designs 323 Review Summary 330 Check Your Progress 331 Key Terms 332 Looking Ahead 332
C H A P T E R 14 Writing and Assembling an APA-Format Research Report 333 What Is APA Format? 333 Sections of the APA-Format Paper 334
Title Page 335 Abstract 336 Introduction 338 Method 343 Results 348 Discussion 353 References 356 Appendix 362 Author Note 362 Headings 363 Review Summary 370 Check Your Progress 370
Writing in APA Style 371 General Guidelines 372 Grammatical Guidelines 373
APA Editorial Style 376 Preparing Your Manuscript 376 Student Views of Professional Activities 379
Review Summary 385 Check Your Progress 386 Key Terms 387 Looking Ahead 387
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Appendix A: Statistical Tables 389
Appendix B: Selected Statistical Formulae 395
Appendix C: Factorial Design with Three Independent Variables 397
Appendix D: Check Your Progress Answers 400
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Because our objectives and goals and the specific features we’ve included in The Psychologist as Detective remain unchanged in this fifth edition, our original Preface follows.
Note to the Instructor Margery Franklin (1990) quoted former Clark University professor and chair Heinz Werner’s views on psychological research. Werner indicated:
I got rather apprehensive at finding that students were frequently taught that there was only one acceptable way of conduct in the laboratory—there has to be an hypothesis set up, or a set of hypotheses, and the main job of the experimenter is to prove or disprove the hypothesis. What is missed here is the function of the scientist as a discoverer and explorer of unknown lands. . . . Hypotheses . . . are essential elements of inquiry, but they are so not as rigid propositions but as flexible parts of the process of searching; by the same token, conclusions drawn from the results are as much an end as a beginning. . . . Now . . . academic psychologists [are beginning] to see research not as a rigid exercise of rules of a game but as a problem solving procedure, a probing into unknown lands with plans which are not fixed but modifiable, with progress and retreat, with branching out into various directions or concentration on one. (p. 185)
Clearly Werner’s views are as applicable in the 21st century as they were during the heyday of behaviorism; they reflect perfectly the intent of this text.
From our vantage point, research in psychology is like a detective case; hence the title we have chosen, The Psychologist as Detective. A problem presents itself; we discover clues; we must evaluate bits of evidence that compete for our attention and accept or discard them; and finally, we prepare a report or summary of the case (research) for consideration by our peers.
When presented in this light, the research process in psychology will, we believe, be an interesting and stimulating endeavor for students. In short, our goal is to attract students to psychological research because of its inherent interest.
To accomplish this goal, we have incorporated several pedagogical features in this text:
1. To provide a sense of relevance and continuity, the theme of “psychologist as detective” runs throughout the text.
2. Interactive Style of Writing. Because we believe that the experimental psychology/ research methods text should be lively and engaging, we employ an interactive, conver- sational style of writing that we hope will help draw students into the material.
3. The Psychological Detective Feature. The questions or situations posed by these sec- tions that appear throughout each chapter will encourage students to engage in critical thinking exercises. These sections also serve as excellent stimulants for productive class discussions.
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4. Marginal Definitions. Key definitions appear in the margin, close to the introduction of the term in the text.
5. Review Summaries. To help students master smaller chunks of material, each chapter contains one or more review summaries.
6. Check Your Progress. A Check Your Progress feature follows each Review Summary. Stu- dents can use these sections to test their mastery of the material they have just com- pleted. These study breaks should be especially helpful to your students when they prepare for quizzes and examinations.
We hope that these special features will provide your students with a positive experience as they learn the fundamentals of research methodology in psychology.
Note to the Student Welcome to the world of psychological research! Because the two of us have taught this course for over 60 years (combined!), we have seen the excitement that research can gener- ate in student after student. As you will learn, conducting psychological research is very much like being a detective on a case.
Throughout this text we have tried to make it clear that research is something that you can (and should) become involved in. We hope you will enjoy reading about the student projects that we use as research examples throughout this text. Student research projects are making valuable contributions to our field. We hope to see your name among those making such contributions!
At this point we encourage you to stop immediately to review the list of pedagogical fea- tures highlighted in the “Note to the Instructor.”
Did you humor us by actually looking at that list? If not, please do so now. To make full use of this text, you need to become actively involved; these pedagogical features will help you. Active involvement means that you need to stop and think about The Psychological Detective sections immediately when you encounter them, refer to figures and tables when directed to do so, and complete the Check Your Progress sections when they appear. Becoming actively involved in this course helps the material come alive; your grade and your future involvement in psychology will thank you.
What’s New for the Fifth Edition? We are excited about the continuing evolution of The Psychologist as Detective: An Introduc- tion to Conducting Research in Psychology. We have implemented several major changes and additions for the fifth edition:
1. Based on feedback from adopters, we have: A. Streamlined the first chapter and sharpened the focus to deal with the general topic of
research methods. B. Devoted a complete chapter (Chapter 3) to the coverage of Qualitative Research Meth-
ods and combined our coverage of other nonexperimental research methods into one, separate chapter.
C. Created a separate chapter to introduce students to the basics of using the scientific methods in psychological research (Chapter 5).
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2. An updated and expanded Instructor’s Manual and Electronic Test Item File are also avail- able to accompany The Psychologist as Detective. Please contact your local Prentice Hall representative or log onto www.pearsonhighered.com.
Acknowledgments We express our appreciation to the consultants who suggested improvements for this text; their comments were especially helpful: Bryan K. Saville, James Madison University; Con- stance Jones, California State University, Fresno; Michael T. Dreznick, Our Lady of the Lake College; Jonathan W. Amburgey, University of Utah; Nancy J. Knous, Northwestern Oklahoma State University; Lauren Mizock, Suffolk University; Roger A. Chadwick, New Mexico State University; Katia Shkurkin, Saint Martin’s University; Oriel Strickland, California State Univer- sity, Sacramento; Keiko Taga, California State University, Fullerton.
And from previous edition reviews: Chris Spatz, Hendrix College; Beth Dietz Uhler, Miami University (Ohio); Janet Larsen, John
Carroll University; Doreen Arcus, University of Massachusetts, Lowell; Lynette Zeleny, California State University, Fresno; Robert Batsell, Kalamazoo College, Scott Gronlund, University of Oklahoma; Laura Bowman, Central Connecticut State University; Celia Brownell, University of Pittsburgh; Lee Fernandez, Yosemite Community College; Michael Brannick, University of Southern Florida; Maureen McCarthy, Kennesaw State University; Elizabeth Yost Hammer, Loyola University; Terry Pettijohn, Mercyhurst College; Gina Grimshaw, California State University, San Marcos. Susan Burns, Morningside College; Mark Stellmack, University of Minnesota; Karen Schmidt, University of Virginia; Morton Heller, Eastern Illinois University; Joy Drinnon, Milligan College; Rebecca Regeth, California University of Pennsylvania; Christina Sinisi, Charleston Southern University; Rick Froman, John Brown University; Libbe Gray, Austin College; Mizuho Arai, University of Massachusetts, Boston; Theresa L. White, Le Moyne College; David E. Anderson, Allegheny College; Jerome Lee, Albright College; Scott A. Bailey, Texas Lutheran University.
R. A. S. S. F. D.
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