an introductory text that focuses on data and on statistical reasoning. It is elementary in mathematical level, but conceptually rich in statistical ideas and serious in its aim to help students think about data and use statistical methods with understanding. Although the first edition of IPS was a somewhat radical departure from the then-standard course, which emphasized probability and inference, this third edition now represents the current standard, in which data analysis, design of data production, and the demands of statis tical practice join probability-based inference as foci for study.