Psychologist as Detective An Introduction to Conducting

The Psychologist as Detective An Introduction to Conducting

Research in Psychology

Fifth Edition

Randolph A. Smith Lamar University

Stephen F. Davis Morningside College

Prentice Hall

Upper Saddle River London Singapore Toronto Tokyo Sydney Hong Kong Mexico City

A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:17 PM Page i

Editorial Director: Leah Jewell Editor in Chief: Jessica Mosher Executive Editor: Jeff Marshall Editorial Project Manager: LeeAnn Doherty Editorial Assistant: Amy Trudell Director of Marketing: Brandy Dawson Marketing Manager: Nicole Kunzmann Assistant Marketing Manager: Laura Kennedy Marketing Assistant: Jennifer Lang Managing Editor: Maureen Richardson Project Liaison: Shelly Kupperman Senior Operations Supervisor: Sherry Lewis Director, Cover Design: Jayne Conte Cover Designer: Lisbeth Axell

This book was set in 9/12 Poppl-Laudatio Light.

Credits and acknowledgments borrowed from other sources and reproduced, with permission, in this textbook appear on appropriate page within text.

Copyright © 2010, 2007, 2004, 2001, 1997 Pearson Education, Inc., publishing as Prentice Hall, 1 Lake Street, Upper Saddle River, NJ 07458. All rights reserved. Manufactured in the United States of America. This publication is protected by Copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. To obtain permission(s) to use material from this work, please submit a written request to: Pearson Education, Inc., Permissions Department, 1 Lake Street, Upper Saddle River, NJ 07458.

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

Macmillan Publishing Solutions/Laura Lawrie Printer/Binder: Edwards Brothers Cover Printer: Coral Graphics

AV Project Manager: Maria Piper Manager, Visual Research: Beth Brenzel Manager, Rights and Permissions: Zina Arabia Image Permissions Coordinator:

Angelique Sharps Manager, Cover Visual Research and Permissions:

Karen Sanatar Cover Art: Boris Lyubner/Illustration Works/Corbis Media Director: Paul DeLuca Supplements Editor: Ginny Livsey Composition/Full-Service Project Management:

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

( to fight this cruel disease.

A01_SMIT7407_05_SE_FM.QXD 2/6/09 3:38 PM Page ii

Preface xii

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



A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page iii

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


A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page iv

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


A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page v

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


A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page vi

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


A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page vii

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


A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page viii

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


A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page ix

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


A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page x

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

Glossary 417

References 427

Index 435


A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page xi

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.



A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page xii


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).

A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page xiii

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

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.


A01_SMIT7407_05_SE_FM.QXD 2/4/09 8:14 PM Page xiv