Although statistical reporting of production and sales of information technology-based goods and services and the performance of the IT industry has improved, new tools are necessary to determine how it is actually used. This book puts forward the development of IT usage indicators -- measurements which capture the quantitative and qualitative impacts of IT in private and public sector applications. Usage indicators can provide insight into such issues as how IT is used in various economic sectors and what are the economic or social results, how many people actually work with computers and other IT and what effect IT has on their work, and how and why IT usage differs among economic sectors and countries. This report presents a new approach to such issues and provides detailed information on IT usage and emerging trends in OECD countries.