- From: Eliot Christian <echristi@usgs.gov>
- Date: Fri, 13 Oct 1995 05:21:16 -0400
- To: gils@cni.org
We're announcing here an alpha release of freeware intended to handle World Wide Web client searching. This software uses the standard search protocol known in the U.S. as ANSI Z39.50 and internationally as ISO 10163. (Support for searching via the WAIS protocol, sometimes referred to as Z39.50 version 1, should be available soon.) This software is intended to address a common problem when people go looking for information--the sources all have different ways of searching. Some are set up for novices, but these can be frustrating because they're not very precise. Others are more precise, but you need information specialist skills to use them. And, if you don't happen to be skilled in English, there are few sources accessible in your native language. These difficulties in searching for information are not well addressed even if you limit your searching to the current Internet-accessible servers. If all you have is a Web browser that understands telnet, FTP, gopher, and HTTP, you have very limited control of your searching. There is a great need for a common search protocol that servers support ubiquitously, and that intelligent clients can use. Then the client can do a much better job of gathering information in ways that fit the particular needs of specific searchers. One solution is to use the Z39.50 client/server search protocol. This is the protocol already supported by hundreds of library databases offering access to billions of dollars worth of bibliographic catalogs. It is also the protocol required for use by all U.S. Federal government agencies, under public law 44 USC 3511 which established the Government Information Locator Service (see http://www.usgs.gov/gils). Other massive applications using Z39.50 are also in progress. This initial freeware implementation is constructed as an add-on to the Netscape WWW browser in Windows (Windows 3.11, Windows95, and Windows NT). We anticipate that other developers will extend this client approach to other WWW browsers, make similar clients for the Macintosh and Unix platforms, and take advantage of CORBA and Java technologies. Using Microsoft's OLE (object linking and embedding), this software is invoked within the WWW browser in response to a URL that refers to a supported search protocol (the software registers the protocols "wais", "z3950r", "z3950s", and "search"). As pointed out by Jim Perkins at the Library of Congress, using OLE opens up the possibility of embedding Internet search functions into all sorts of applications (e-mail, spreadsheets, databases, travel planners, ...). After all, people don't search for information as an end in itself, they are usually trying to accomplish some other goal. Because the software uses the computer to computer Z39.50 protocol to actually conduct the search, the client can be completely customized to the specific needs of the searcher. This is especially attractive when you consider the alternatives--either searching many servers with different HTML forms, or using a Web crawler designed to be "one size fits all". The software produces a user interface by constructing HTML forms on the local disk drive. Since this is done locally on the client, one could customize the interface for novices or experts, and in whatever language you want. Also, for cases where the human user isn't immediately present, the software could gather information on its own and construct a new database--perhaps to create a personalized newspaper. Although simple text search and retrieval is available on all Z39.50 servers, servers differ quite a bit when you start to use more precise searching techniques. For example, Z39.50 servers may have different elements that are searchable and may support features like stemming of search terms or phonetic spellings. This alpha software supports having multiple configurations that specify these differences. An obvious enhancement would be for the client software to obtain these configuration specifics dynamically through the Z39.50 Explain facility on compliant servers. Another obvious enhancement would be to take advantage of Z39.50 to conduct distributed search among multiple servers. This alpha software just searches one database at a time. In anticipation of servers now becoming available for geospatial searching, the alpha software helps the user to designate spatial coordinates (decimal latitude/longitude value) as search criteria. A geospatial server conforming to the GEO Profile of Z39.50 is under construction by the Clearinghouse for Networked Information Discovery and Retrieval. It is not hard to envision more general kinds of pattern-matching building on this idea of standardized client-server approach for information search, e.g., gene sequences, fingerprints, faces, images of the Earth. Although this software is not yet a fully developed product, you are welcome to check out what's been built so far--especially if you are interested in helping to elaborate this approach. The primary developer is Jeff Gelbard, subcontracted through the University of Massachusettes, Center for Intelligent Information Retrieval (CIIR), which has a development contract with the U.S. Defense Technical Information Center (DTIC). The Z39.50 protocol stack code is the property of Ameritech but is being made available in this product for individual use at no charge. (If you wish to license the Z39.50 protocol stack code for use in a commerial product, please send me e-mail and I'll get you in touch with Ameritech.) Except for the Z39.50 protocol software, all source code is being placed in the public domain. You can fetch the executable software, README.TXT, and source files by anonymous FTP to host www.usgs.gov, in the directory /gils/ciir/dtic_a02. If there is a lot of interest, we will set up a listserve for discussing this and related client software. If you would be interested in joining such a list, or have any other comments about the client software, please send e-mail directly to me for now. Eliot Christian, US Geological Survey, 802 National Center, Reston VA 22092 echristi@usgs.gov Office 703-648-7245 FAX 703-648-7069 Home 703-476-6134
Received on Friday, 13 October 1995 06:16:59 UTC