NOAA site offers up wealth of data

With recent additions and planned improvements, the National Environmental Data Index World Wide Web site is a useful stop on the Internet for anyone interested in environmental and scientific data maintained by federal agencies.

The National Oceanic and Atmospheric Administration hosts the NEDI (www.nedi.gov) site, which the agency promotes as the Yellow Pages of environmental data. This portal site provides a listing of environmental data produced by federal agencies and a link to where the information can be located. In some cases, a user can link directly to an actual document, such as a piece of legislation or a press release.NEDI covers a wide variety of data, including information on weather, space weather, water quality, vegetation and wetlands, and visitors to the site are diverse, according to Chris Miller, project manager for NEDI. About 30 percent to 40 percent of visitors have a ".com" address, while 20 percent have an ".edu" address and about 20 percent have a ".gov" address, Miller said. NOAA launched NEDI in 1994 based on a recommendation by Vice President Al Gore's then-National Performance Review.

NEDI is a distributed search engine, which means it uses the data and search engines of the contributing agencies, said Bob Freedman, technical lead for NEDI. "We use a mix of Java and Perl [Practical Extraction and Reporting Language] to send queries to many different databases simultaneously," he said. The results from the different agencies are collected and presented to users in a unified format, Freedman said. Users then choose particular headlines that are sorted by agency and data source. This enables them to view the article or metadata record—a locator system that describes data holdings—directly from the source.

"Because we don't put any burden on the data source in terms of configuration of hardware and software or how to set up fields, we are getting what [agencies] want to make available to the system," Miller said. In some cases, the information is robust, and in other cases, it is cryptic, he said.

NEDI searches across indexes maintained by most federal agencies including the departments of Agriculture, Commerce, Defense, and Health and Human Services as well as the Environmental Protection Agency. Recently, NOAA added listings from the Transportation Department, including the Coast Guard and the Federal Aviation Administration, and the Federal Emergency Management Agency.

In addition to expanding the number of listings NEDI can search across, NOAA plans to add a thesaurus to the search page, making search results more complete. For example, if a term is ambiguous, the thesaurus will help the user look at other variations of the word to identify the specific meaning intended. The agency also plans to add a map of the world so that a user can click on a particular region of interest.

However, although NEDI represents a monumental undertaking, it is not very user-friendly or fast. For example, there is little guidance to the user on how a search should be conducted, including how best to narrow a search. Which agency or type of document would have the best data on river pollution, for example? NEDI offers no help in answering those types of questions, but it offers up a wealth of resources for those interested in the science and environmental data community.