Explaining Psychological Statistics

Praise for the previous edition of Explaining Psychological Statistics

"I teach a master's level, one-semester statistics course, and it is a challenge to find a textbook that is at the right level. Barry Cohen's book is the best one I have found. . . . I like the fact that the chapters have different sections that allow the professor to decide how much depth of coverage to include in his/her course. . . . This is a strong and improved edition of an already good book."

—Karen Caplovitz Barrett, PhD, Professor, and Assistant Department Head of Human Development and Family Studies, Colorado State University

"The quality is uniformly good. . . . This is not the first statistics text I have read but it is one of the best."

—Michael Dosch, PhD, MS, CRNA, Associate Professor and Chair, Nurse Anesthesia, University of Detroit Mercy

A clear and accessible statistics text— now fully updated and revised

Now with a new chapter showing students how to apply the right test in the right way to yield the most accurate and true result, Explaining Psychological Statistics, Fourth Edition offers students an engaging introduction to the field. Presenting the material in a logically flowing, non-intimidating way, this comprehensive text covers both introductory and advanced topics in statistics, from the basic concepts (and limitations) of null hypothesis testing to mixed-design ANOVA and multiple regression.

The Fourth Edition covers:

• Basic statistical procedures
• Frequency tables, graphs, and distributions
• Measures of central tendency and variability
• One- and two-sample hypothesis tests
• Hypothesis testing
• Interval estimation and the t distribution

BARRY H. COHEN, PhD, is a clinical associate professor in the department of psychology at New York University, where he has been teaching statistics for more than twenty-five years. He is the coauthor of two other successful statistics books from Wiley: Introductory Statistics for the Behavioral Sciences, Seventh Edition and Essentials of Statistics for the Social and Behavioral Sciences.

Preface to the Third Edition xxv

Acknowledgments xxxi

Part One Descriptive Statistics 1

Chapter 1 Introduction To Psychological Statistics 1

Chapter 2 Frequency Tables, Graphs, And Distributions 21

Chapter 3 Measures Of Central Tendency And Variability 46

Chapter 4 Standardized Scores And The Normal Distribution 87

Part Two One- and Two-Sample Hypothesis Tests 123

Chapter 5 Introduction to Hypothesis Testing: The One-Sample z Test 123

Chapter 6 Interval Estimation and the t Distribution 156

Chapter 7 The t Test for Two Independent Sample Means 188

Chapter 8 Statistical Power and Effect Size 222

Part Three Hypothesis Tests Involving Two Measures on Each  Subject 255

Chapter 9 Linear Correlation 255

Chapter 10 Linear Regression 286

Chapter 11 The Matched t Test 317

Part Four Analysis of Variance without Repeated Measures 342

Chapter 12 One-Way Independent ANOVA 342

Chapter 13 Multiple Comparisons 386

Chapter 14 Two-Way ANOVA 425

Part Five Analysis of Variance with Repeated Measures 487

Chapter 15 Repeated Measures ANOVA 487

Chapter 16 Two-Way Mixed Design ANOVA 528

Part Six Multiple Regression and Its Connection to ANOVA 571

Chapter 17 Multiple Regression 571

Chapter 18 The Regression Approach to ANOVA 627

Part Seven Nonparametric Statistics 677

Chapter 19 The Binomial Distribution 677

Chapter 20 Chi-Square Tests 700

Appendix A Statistical Tables 757

Appendix B Answers To Selected Exercises 777

References 799

Index 807