pThis Handbook provides a wide-ranging and comprehensive coverage of statistical concepts and methods. It has been designed to be accessible to a wide range of readers - from undergraduates and postgraduates studying statistics and statistical analysis as a component of their specific discipline e.g. social sciences, earth sciences, life sciences, engineers, to practitioners and professional research scientists. However, it is not intended to be a guide for mathematicians, advanced students studying statistics or for professional statisticians. For students studying for academic or professional qualifications in statistics, the level and content adopted is that of the Ordinary and Higher Level Certificates of the Royal Statistical Society RSS, offered until 2017. Much of the material included in this Handbook is also appropriate for the Graduate Diploma level also, although we have not sought to be rigorous or excessively formal in our treatment of individual statistical topics, prefer