Teams working on performance audits and value for money studies have to draw on a range of methodologies and techniques to help them form robust conclusions. Using statistical methods to interrogate quantitative evidence is one of the specialist methods that can add considerable value to audit work. Statistical techniques can be used to provide clear measures of costs, benefits and performance. They can also help to assess the strength of evidence when investigating audit questions, and to ensure that conclusions and recommendations are well-founded and evidence-based.The handbook is a guide on how statistical methods can be applied in performance audit and value for money work. It can be used as a source of reference on particular techniques; to provide background when dealing with specialist statistical consultants; or as a textbook on applied quantitative methodology. It is illustrated throughout with real examples based on actual audit data, and gives examples of how to interpret basic statistical information, as well as providing an introduction to the principles underlying statistically valid reasoning on the basis of such information.