SEARCH TOOLS: A data index is useless if the user finds so many references to data that evaluating them becomes onerous. Hence one important suite of tools for early implementation are those tools that support improved data search and browse. Tools for this provide a series of functions ranging from the initial discovery of the existence of relevant data, prioritizing data most likely to fit the intended purpose, through location of the data, examination of the metadata, including spatial and temporal coverage, and finally browsing through the data itself to ensure its fitness for the intended purpose.

Activities beyond setting up the initial system all revolve around the need to make the system more useful to the public and general user. The following search enhancements have been identified for ensuring that the most useful data are returned to the user; not just all data.

Thesaurus-assisted Search. A thesaurus can ensure that the user finds the most appropriate data. In the event that a term is ambiguous, the thesaurus will help the user identify the specific meaning intended. This will require identifying an appropriate thesaurus, procuring and integrating the search software and deploying the enhanced capability.

Spatial Searching. Current methods of forming spatial searches are very restrictive requiring the user to know coordinates of the desired area. More useful methods include graphical "rubber-banding" and named-area searches. These techniques are being explored by USGS and will be incorporated as they become available.

Associative-Concept Navigation. This tool provides a method of quickly finding sophisticated descriptors such as noun phrases. These are useful to all users, even the expert, because they provide more precise descriptions of the entity required. While much of this functionality is available through Boolean operators, indexed associative noun phrases provide a much faster response to a query over a large distributed data base.

In these areas the NEDI will be coordinated with existing Federal and non-federal directory efforts.

NON-FEDERAL DATA: The second phase of the Index will require expansion to other data sets outside the Federal Government. The FGDC Clearinghouse and NBII Clearinghouse will provide access to data from states and private (non-profit and commercial) organizations.. However, reaching out to non-participating governmental, commercial, and academic institutions will be a difficult process. Also, international data sources need to be tapped since many environmental problems cross national boundaries. Initial efforts are underway through the IDN (International Directory Network - which has been most successful in the area of satellite data) and GOIN (Global Observing and Information Network), and through the NAFTA framework. The World Data Center system holds much of the internationally available data and so is a potential partner in a Global Environmental Data Index. Detailed plans for the further implementation and expansion of these systems should await phase one of the implementation.

* Environmental data and information: qualitative or quantitative information describing physical, chemical, biological, or ecological characteristics and processes of the Earth. This information includes knowledge about people, plants and animals, fresh and marine waters, surface and subsurface geologic materials and structures, the atmosphere and ice. Also, environmental data and information include the factors and stressors that cause Earth's physical, chemical, biological, and ecological characteristics to change. (return)