• This time around, we added more than 100 new references to this edition in order to show students the most recent psychological findings.

• New photos and drawings have been added to stimulate students' interest.

• We echo a message that was heard in previous editions: A multimethod approach to hypothesis testing is necessary to meet the goals of scientific psychology. All methodologies are limited and it is only by gathering evidence using many different approaches that we will succeed in our task.

• We include Challenge Questions at the end of each chapter that permit students to test their critical thinking skills. Many of these questions were developed from reports of research findings in the media.

CHANGES IN THE FIFTH EDITION

• Bullet Points: Users of previous editions will immediately recognize an important new pedagogical feature in this edition. Within each chapter we have added "bullet points" to the introduction of major sections. These bullet points represent summaries of the main ideas in each section and serve two major purposes. First, they provide an outline of the next section of text for the student. This alerts students to what will follow and guides their study. A second purpose of the bullet points is to provide an easy method of review after the text has been studied. Students can make use of these outlines of key points to help summarize their knowledge of the chapter contents.

• Tips and Strategies: In Chapter 1 we expanded our coverage of "Getting Started Doing Research". Most of us need help when learning to perform a complex task and the tips given by these experts can help students begin to think about the complex task of doing psychological research. Instructors may wish to call attention to these strategies when discussing research studies used to illustrate various methodologies or to incorporate them when planning student research projects.

• Approach to Statistical Analysis: And as authors of an introductory textbook on research methods we find ourselves in a quandary. How do we introduce students to techniques of statistical analysis in a way that is sensitive to important issues in this area and also prepare them to digest current research reports? Our response has been to make significant changes in the way in which we treat statistical analysis in this edition. The most obvious change will be seen in the appendix material, which has been completely rewritten. A new appendix is titled "Data Analysis and Interpretation" and replaces the previous appendix, which had mainly a how-to-do-it emphasis. The statistical appendix in this edition is a tutorial on analysis and interpretation of results based on our understanding of the issues as presented by experts in our field.

• Improvement by Chapter: In the chapter material we continue in this edition to identify for students how statistical analysis and methods are intertwined. In Chapter 4 for example, we open the door to more complex correlational analysis with a (new) brief illustration of path analysis. In the experimental chapters (6-8) we again emphasize analysis of variance techniques in conjunction with effect size analyses, but also (in Chapter 6) illustrate graphical interpretation and the use of confidence intervals when confirming what data tell us. In this way we were able to illustrate difficult statistical concepts in the context of interesting contemporary psychological research, which is our never ceasing goal when revising.

• A new sample APA manuscript is found in this edition. The topic of the new sample paper is false memory and is written to illustrate the most current recommendations of APA regarding report writing (e.g., including power analyses and effect size measures when reporting results). Like its predecessor, however, the manuscript details an actual research study.

• Web-site: Both students and instructors using this edition will also benefit from a new web site that was designed for this book. Much of the material that was published before in a workbook written to accompany the major text is now found on this web site. There are exercises and quizzes for students to test their knowledge of text material, as well as links to other important psychology web sites.