This book explores the reliability of official statistical data in the ASEAN (the Association of Southeast Asian Nations), and the benefits of a better vocabulary to discuss the quality of publicly available data to address the needs of all users. It introduces a rigorous method to disaggregate and rate data quality into principal factors containing a total of ten dimensions, which serves as the basis for a discussion on the opportunities and challenges for data quality, capacity building programs and data policy in Southeast Asia. Tools to standardize and monitor statistical capacity and data quality are presented, as well as methods and data sources to analyse data quality. The book analyses data quality in Indonesia, Malaysia, Singapore, the Philippines, Thailand, Vietnam, Brunei, Laos, Cambodia, and Myanmar, before concluding with thoughts on Open Data and the ASEAN Economic Community (AEC). .