There are some major additions and deletions for this edition. A new unit which covers the issue of the lack of homogeneity of variance. New sections covering research issues and strategies in the area of criminal justice. Inclusion of smaller data sets for students to practice. Research examples have been updated and carefully chosen for student interest as well as pedagogical purposes. A new section, the statistical Rosetta Stone, illustrates all of the statistical symbols in the book for a quick reference for students.