The thirteenth edition of Principles of Auditing and Other Assurance Services provides a carefully balanced presentation of auditing and assurance theory and practice. Written in a clear and understandable manner, it is appropriate for students who have not had significant audit experience. The approach is to integrate auditing and assurance material with that of previous courses in accounting systems and financial and managerial accounting. Our primary goal is to provide a textbook well suited for the introductory one semester or one quarter auditing and assurance course. - Preface.