The 179-page book is for courses in applied statistics, particularly for policy making and the social sciences. It deals with making causal inferences from statistical evidence, research designs, predictions and projections, linear and multiple regression. All the examples are real, involving serious questions (no regressions of height on weight that are found in some statistics texts). The technical material is at the level of one or two classes in college math. There is one somewhat more technical part, on logarithmic scale transformations and their interpretation in regression and in graphics. The book was written very much under the influence of Frederick Mosteller, John Tukey, and my professor of statistics at Stanford, Lincoln Moses.