Online video¿s unique capacity to reach large audiences makes it a powerful tool to communicate science and technology to the general public. The outcome of the international research project "Videonline," this book provides a unique insight into the key elements of online science videos, such as narrative trends, production characteristics, and issues of scientific rigor. If offers various methodological approaches: a literature review, content analysis, and interviews and surveys of expert practitioners to provide information on how to maintain standards of rigour and technical quality in video production.