This edition covers ethics of animal research up to date, primarily by incorporating the thoughtful treatment of the issue by Hal Herzog in his recent text about human-animal interaction. It closes with a discussion of how to review the literature with a new section that includes specific tips on how to organize and write a literature review. This issue also includes a discussion of effect size, power, and meta-analysis, especially by showing the manner in which they are interrelated and significantly increases coverage of the methods used and the issues involved with conducting online research.