It has been long understood that the generation, exploitation and diffusion of knowledge are fundamental to economic growth, development and the well being of nations. Central to this is the need for better measures of innovation. Over time the nature and landscape of innovation have changed, and so has the need for indicators to capture those changes and provide policy makers with appropriate tools of analysis. A considerable body of work was undertaken during the 1980s and 1990s to develop models and analytical frameworks for the study of innovation. Experimentation with early surveys and their results, along with the need for a coherent set of concepts and tools led to the first edition of the Oslo Manual in 1992, which focused on technological product and process (TPP) innovation in manufacturing. This became the reference for various large scale surveys examining the nature and impacts of innovation in the business sector, such as the European Community Innovation Survey (CIS), currently in its fourth round. Results from such surveys have driven further refinements in the Oslo Manual framework in terms of concepts, definitions and methodology leading to second edition published in 1997 which, among other things, expanded coverage to service sectors. Since then, the analysis of results from surveys and changing policy needs led to the launching of another revision of the manual, the result of which can be found in this third edition. As there has been a growing sense that much of innovation in service sectors is not adequately captured by the TPP concept, it was decided to address the question of non technological innovation in this revision. As a result, the scope of what is considered an innovation has now been expanded to include two new types: marketing and organisational innovation. These are certainly new concepts, but they have already been tested in several OECD countries, with promising results. New to this edition is also an effort to address the systemic dimension of innovation, through a chapter focusing on innovation linkages. Lessons drawn from results of previous surveys have also been incorporated in order to refine existing concepts and methodological issues, such as the measurement of innovation inputs and outcomes, as well as the improvement of data collection methods. Innovation also occurs outside the OECD region: a growing number of countries in Latin America, Eastern Europe, Asia and Africa have begun undertaking surveys based on the Oslo Manual. Although the design of those surveys was usually intended to comply with such standards, many of them have adapted the Oslo methodology to take into account specific user needs and the characteristics of statistical systems in these countries with different economic and social backgrounds. National adaptations were developed by each country and followed different approaches. For example, it is widely accepted that diffusion and incremental changes to innovation account for much of the innovation occurring in non OECD countries. Using these rich and diverse experiences, an annex has been added to this edition of the Oslo Manual that draws on some of the lessons learned, and provides further guidance for future innovation surveys in non OECD countries. The Oslo Manual, developed jointly by Eurostat and the OECD, is part of a continuously evolving family of manuals devoted to the measurement and interpretation of data relating to science, technology and innovation. This includes manuals, guidelines and handbooks covering R&D (Frascati Manual), globalisation indicators, patents, the information society, human resources in S&T (Canberra Manual), and biotechnology statistics. Prepared under the joint aegis of the OECD and the European Commission (Eurostat), this third edition of the Oslo Manual is the result of a three year collaborative process that has involved the OECD Working Party of National Experts on Science and Technology Indicators (NESTI) and the Eurostat Working Party on Science, Technology and Innovation Statistics (WPSTI) as well as a number of outside experts. This manual provides guidelines for collecting and interpreting innovation data in an internationally comparable manner. Finding consensus has sometimes meant reaching compromises and agreeing to conventions. As with other such guidelines, there are known limitations, but each edition of the Oslo Manual constitutes a step forward in our understanding of the innovation process. While this ongoing, incremental learning incorporates the lessons of earlier studies, the Manual is also an ambitious tool in which experimentation and testing are used to challenge the boundaries of what is understood by innovation. Many should be thanked for their valuable contributions. A special acknowledgement goes to experts from Canada, France, Germany, Italy, Japan, the Netherlands, Norway and the United Kingdom who led the work of six focus groups which examined a variety of topics and expressed valuable recommendations for the revision. The drafting of the revised Oslo Manual was undertaken by Dr. Peter Mortensen and Dr. Carter Bloch from the Danish Centre for Studies in Research and Research Policy, under the guidance of the OECD and Eurostat. The annex on innovation surveys in developing countries was drafted by the UNESCO Institute for Statistics, based on a proposal and draft paper by the Red Iberoamericana de Indicadores de Ciencia y Tecnología (RICYT) and following a broad process of consultation with many national experts.