reiterated in a 1998 report, Geographic Information for the 21st Century: Building a Strategy for the Nation (NAPA, 1998), in which the National Academy of Public Administration identified the NSDI as an important national priority for the United States.
At the core of the NSDI is the concept of partnerships, or collaborations, among different agencies, corporations, institutions, and levels of government. Partnerships are designed to share the costs of creation and maintenance of geospatial data, in order to avoid unnecessary duplication, and to make it possible for data collected by one agency at a high level of spatial detail to be used by another agency in more generalized form. The concept of NSDI partnerships specifically does not refer to joint data ownership, but rather emphasizes the mutual advantages arising from collaboration between partners. Partnerships provide a mechanism for augmenting a system of centralized production of geospatial data, where one (usually national) agency has assumed all of the responsibility and cost, so that the data may be disseminated through a coordinated but diverse patchwork of arrangements that is more suited to meeting local needs. The concept was elaborated in a 1994 NRC report, Promoting the National Spatial Data Infrastructure through Partnerships (NRC, 1994), which suggests that given a network of partnerships and effective coordination among partners, the NSDI has enormous potential to minimize the redundant collection of spatial data, to increase citizen participation in decision making, to improve information available to support decision making at all levels of government and the private sector, and generally to sustain the economic well-being of the nation.
Considerable progress has been made in the evolution of the NSDI in the seven years since 1994. For example, the Open GIS Consortium (OGC, 2001), a not-for-profit organization with more than 200 corporate, agency, and institutional members, has made much progress in overcoming the lack of interoperability between geospatial datasets and software systems. Of particular interest is the Web Mapping Testbed, which demonstrates that diverse datasets residing on distributed servers can be combined into a common view through a simple browser interface. Many partnerships have been formed, often at the instigation or with the financial support of federal programs. These partnerships have taken many different forms with many different sets of objectives. The NSDI continues to expand and to reach into new areas of application.