Research Methods in Psychology: Evaluating a World of Information (Third Edition)

Book Preface

Students in the psychology major plan to pursue a tremendous variety of careers— not just becoming psychology researchers. So they sometimes ask: Why do we need to study research methods when we want to be therapists, social workers, teachers, lawyers, or physicians? Indeed, many students anticipate that research methods will be “dry,” “boring,” and irrelevant to their future goals. This book was written with these very students in mind—students who are taking their first course in research methods (usually sophomores) and who plan to pursue a wide variety of careers. Most of the students who take the course will never become researchers themselves, but they can learn to systematically navigate the research information they will encounter in empirical journal articles as well as in online magazines, print sources, blogs, and tweets.

I used to tell students that by conducting their own research, they would be able to read and apply research later, in their chosen careers. But the literature on learning transfer leads me to believe that the skills involved in designing one’s own studies will not easily transfer to understanding and critically assessing studies done by others. If we want students to assess how well a study supports its claims, we have to teach them to assess research. That is the approach this book takes.

Students Can Develop Research Consumer Skills

To be a systematic consumer of research, students need to know what to prioritize when assessing a study. Sometimes random samples matter, and sometimes they do not. Sometimes we ask about random assignment and confounds, and sometimes we do not. Students benefit from having a set of systematic steps to help them prioritize their questioning when they interrogate quantitative information. To provide that, this book presents a framework of three claims and four validities, introduced in Chapter 3. One axis of the framework is the three kinds
of claims researchers (as well as journalists, bloggers, and commentators) might make: frequency claims (some percentage of people do X), association claims (X is associated with Y), and causal claims (X changes Y). The second axis on the framework is the four validities that are generally agreed upon by methodologists: internal, external, construct, and statistical.

The three claims, four validities framework provides a scaffold that is reinforced throughout. The book shows how almost every term, technique, and piece of information fits into the basic framework.

The framework also helps students set priorities when evaluating a study. Good quantitative reasoners prioritize different validity questions depending on the claim. For example, for a frequency claim, we should ask about measurement (construct validity) and sampling techniques (external validity), but not about random assignment or confounds, because the claim is not a causal one. For a causal claim, we prioritize internal validity and construct validity, but external validity is generally less important.

Through engagement with a consumer-focused research methods course, students become systematic interrogators. They start to ask more appropriate and refined questions about a study. By the end of the course, students can clearly explain why a causal claim needs an experiment to support it. They know how to evaluate whether a variable has been measured well. They know when it’s appropriate to call for more participants in a study. And they can explain when a study must have a representative sample and when such a sample is not needed.

What About Future Researchers?
This book can also be used to teach the flip side of the question: How can producers of research design better studies? The producer angle is presented so that students will be prepared to design studies, collect data, and write papers in courses that prioritize these skills. Producer skills are crucial for students headed for Ph.D. study, and they are sometimes required by advanced coursework in the undergraduate major.
Such future researchers will find sophisticated content, presented in an accessible, consistent manner. They will learn the difference between mediation (Chapter 9) and moderation (Chapters 8 and 9), an important skill in theory building and theory testing. They will learn how to design and interpret factorial designs, even up to three-way interactions (Chapter 12). And in the common event that a student-run study fails to work, one chapter helps them explore the possible reasons for a null effect (Chapter 11). This book provides the basic statistical background, ethics coverage, and APA-style notes for guiding students through study design and execution.

Organization
The fourteen chapters are arranged in six parts. Part I (Chapters 1–3) includes introductory chapters on the scientific method and the three claims, four validities framework. Part II (Chapters 4–5) covers issues that matter for any study: research  Support for Students and Instructors xi ethics and good measurement. Parts III–V (Chapters 6–12) correspond to each of the three claims (frequency, association, and causal). Part VI (Chapters 13–14) focuses on balancing research priorities.

Most of the chapters will be familiar to veteran instructors, including chapters on measurement, experimentation, and factorial designs. However, unlike some methods books, this one devotes two full chapters to correlational research (one on bivariate and one on multivariate studies), which help students learn how to interpret, apply, and interrogate different types of association claims, one of the common types of claims they will encounter.

There are three supplementary chapters, on Descriptive Statistics, Inferential Statistics, and APA-Style Reports and Conference Posters. These chapters provide a review for students who have already had statistics and provide the tools they need to create research reports and conference posters. Two appendices—Random Numbers and How to Use Them, and Statistical Tables—provide reference tools for students who are conducting their own research.

Support for Students and Instructors
The book’s pedagogical features emphasize active learning and repetition of the most important points. Each chapter begins with high-level learning objectives— major skills students should expect to remember even “a year from now.” Important terms in a chapter are introduced in boldface. The Check

Your Understanding
questions at the end of each major section provide basic questions that let students revisit key concepts as they read. Each chapter ends with multiple-choice Review Questions for retrieval practice, and a set of Learning Actively exercises that encourage students to apply what they learned. (Answers are provided at the end of the book.) A master table of the three claims and four validities appears inside
the book’s front cover to remind students of the scaffold for the course. I believe the book works pedagogically because it spirals through the three claims, four validities framework, building in repetition and depth. Although each chapter addresses the usual core content of research methods, students are always reminded of how a particular topic helps them interrogate the key validities. The interleaving of content should help students remember and apply this questioning strategy in the future. I have worked with W. W. Norton to design a support package for fellow instructors and students. The online Interactive Instructor’s Guide offers in-class activities, models of course design, homework and final assignments, and chapter-by-chapter teaching notes, all based on my experience with the course.

The book is accompanied by other ancillaries to assist both new and experienced research methods instructors, including a new InQuizitive online assessment tool, a robust test bank with over 750 questions, updated lecture and active learning slides, and more; for a complete list, see