Two objectives dominated our throught process during this revision. First, we wanted to make the core material shorter and clearer. We have always sought to communicate ideas in an understandable manner; reviewers tell us this is a major strength of the text. Nonetheless, precision and clarity were priorities in this revision. We literally went over every sentence and paragraph asking ourselves if it was really necessary and how we might make the central points easier for readers to grasp. As a result, the core theory chapters are about 10 percent shorter than in the last edition.
Second, this edition is more visual. We want to make it easier for readers to ”see” important relations.