consistent method for monitoring changes in land use and land cover. The detection of key changes in geospatial data, the description and measurement of change, and the analysis and modeling of change are required for many applications. For example, in order to meet programmatic goals—such as: “Analyze land use change in large metropolitan areas using USGS-derived temporal data” (UDRP, 2001)—it is essential to have the supporting spatial information. Partnership programs that utilize the NSDI Framework data for change detection or analysis for specific applications would be valuable as a means to ensure that the NSDI resources support this functionality adequately, and also to develop tools and methodologies for change detection and analysis in the NSDI context. This would make an important contribution toward the goal of increasing the use of geospatial data to address real-world decision-making needs. A data archiving function could become a standard task for the NSDI organization itself (i.e., centralized archiving) or it could fall within the responsibility of the contributing partner organization. From a future partnership perspective, this issue should be addressed in order to develop guidelines and assistance to partner agencies to help ensure that data are being appropriately archived. Again, since consistency is so important, guidelines by theme (and scale) will be required, as will technological tools that can assist data contributors in maintaining old versions of their NSDI-relevant data and making them available to users. All of these extended services rest on the same basic assertions: that through partnerships, the NSDI will reduce costs and duplication and improve accuracy and access.

Because the NSDI network of information assets, including Framework data, will not be comprised entirely of public-domain data, many of these information assets will be subject to concerns about privacy, private and public rights, and free use versus pay-for-use. To exclude these latter assets would result in a watered-down, more expensive (from a taxpayer’s if not a user’s perspective), less detailed, less accurate, and hence less useful NSDI. Therefore, these

issues must be addressed, and future partnership programs should be responsible for establishing the policies, tools, and systems needed for an NSDI that can adequately handle private-sector as well as public-sector data, confidential as well as non-confidential data, and free-use as well as restricted-use data. Partnership programs dealing with public-sector data which may have some associated privacy or confidentiality concerns (e.g., dealing with individual-level property information in a cadastral dataset) should identify or develop guidelines and tools for dealing with this issue in a way that prevents the unauthorized or inappropriate use of such data, yet still makes available as much of the information as possible without violating privacy or confidentiality guidelines.

It must be noted that many of the challenges that face the development of the NSDI based on public private partnerships are being addressed by the private sector. One example is MicroSoft’s establishment of the Terraserver, which provided free access to federal data and images. Another example is Environmental Systems Research Institute’s Geography Network. The Geography Network is “a concept that promotes the sharing and distribution of geospatial information via the Web, allowing consumers to have access to information that will allow them to understand their geography and apply this to their everyday and business use” (ESRI, 2001a). Using the fundamental power of the Internet, contributors publish links to web servers that house their geographic data. In this manner the contributor remains the custodian of the data and is free to establish its own data maintenance program. In many ways the Geography Network represents an alternative to the FGDC data clearinghouses. However, according to ESRI (2001a):

While still in its infancy, the Geography Network appears to have gained favor with a wide range of public and private data pro-

viders and represents an intriguing business model. The Texas Natural Resources Information System, the New Jersey Office of GIS, the Pennsylvania Spatial Data Access, and the USGS, for example, are all using the Geography Network to disseminate public domain data, while private data providers, such as Geographic Data Technology, are using the same system to collect fees for their proprietary data. In this manner the Geography Network is a combination of a geospatial library and an e-business venture. A unique feature of the system is that it allows for a preview of data before any fees are charged for the actual data transfer. It is interesting to note, that in the open environment of the Internet, the FGDC data clearinghouse nodes could become part of The Geography Network. Clearly, The Geography Network will enhance the concept of the NSDI by potentially providing a highly popular and robust starting point for the search of the most complete inventory of spatial data for any part of the world. The ultimate success will be judged by the public in terms of performance, completeness, and ease of use, however, it must also be noted that The Geography Network relies on contributors who have adopted FGDC metadata and content standards. It could be argued that this is exactly the type of public private partnership that will make the NSDI a reality.

Private-sector participation in the NSDI will require that guidelines be established and mechanisms put in place to manage users’ access to licensed datasets or elements. Much work needs to be done first to develop the policy for integrating private-sector data within the NSDI (e.g., Will Framework data be completely public domain or free access? Can a free-access version of Framework be made available for those unable or unwilling to pay for data access, as well as a fee-based version for those who will pay? Is it possible to establish consistency in pricing policies?), and then to establish the infrastructure needed to manage access, licensing, and fees. This process should take full advantage of the ever-improving state-of-the-art in e-commerce tools, particularly those dealing with selling digital goods, such as Qpass, which manage the sale and distribution of information from other sites, such as image repositories (e.g., Corbis, 2001), financial databases, and news databases (Qpass, 2001).

To address the public-access issue, it may be feasible to implement a public-use category that is free in all cases, even when