There is growing interest internationally in the role that Spatial Data Infrastructures SDIs play as key tools in supporting sustainable development. SDIs, as defined in the context of this book, are network-based national solutions to provide easy, consistent and effective access to geographic information and services by public agencies and others. The intention is for SDIs to support of political, economic, social and personal development and include the technology, policies, standards, human resources, and related activities necessary to support its goals. Many jurisdictions are investing in distributed, interconnected SDIs that will enable their stakeholders to work better together and make better decisions. However, every nation implements and uses SDIs in different ways. They are expensive to create in terms of financial and human resources and need to continually adapt to meet changing societal and technological conditions. Both developed and developing countries accept the need to evaluate SDIs to help identify areas of improvement and whether their systems are capable of addressing future needs. Countries are continually re-engineering and implementing various aspects of SDIs, comparing systems and trying to identify best practices within and among nations. The hierarchical nature of SDIs means that in order for local to national to global effectiveness and interoperability to be achieved, some form of SDI comparison, evaluation and assessment is needed at all levels and among the approaches being pursued. Appropriate technologies are a necessary but insufficient prerequisite for effective SDIs. Comparisons among technological implementations are important but research has found that frameworks for establishing a spatial infrastructure need to also comprehensively address operational, organisational and legal issues. It is these constraints that if met enable the infrastructure to be readily useable and available to all stakeholders. Nations and jurisdictions at all levels need rational means to assess and monitor the development and performance of these aspects of their infrastructures. The development of SDIs involves a wide cross section of partners from government, industry and academia, each with different perspectives relative to how well an SDI is meeting its needs. Therefore, societal sectors and individuals within those sectors also have different perspectives in regard to how an SDI should be assessed. Private industry may look for an infrastructure they can build upon to create useable products and services that may be sold for commercial profit. Government agencies may be most concerned with increasing efficiencies and effectiveness to meet government needs, or in creating services desired by citizens directly from government. Academia and non-profit organisations may be most interested in gaining access to government data to pursue their own processing and analysis for education, research or other social goals. Well designed and implemented SDIs support effective applications and value adding activities by, and for, broad constituencies that are both internal and external to government. To find those SDI models that best balance the needs of the many involved constituencies requires a multi-view approach and an ongoing evaluation and assessment of SDIs. While previous SDI assessment initiatives have provided useful and valuable outcomes and concepts upon which to build, the authors in this volume have focused on developing a framework to accommodate multiple views as a key cornerstone of the assessment process. The book provides a comprehensive assessment framework for SDIs, taking into account the different views and perspectives from which SDIs may be assessed. It is an important and welcome addition to sharing knowledge and practice in regard to assessing SDIs. @en