Z39.50 is the fou ndation for WAIS' search approach, although experts say WAIS has customized the standard, which in some instances proved too complex and in others lacking. One of the key advantages of Z39.50 is that it lets users retain their search history as they continue to search a server. It lets content providers build indexes for their databases and expand those indexes in a hierarchical tree structure when they become too large for a single server to handle. The approach relies on pointers, so that a user searching for particular information will be expeditiously directed through the tree structure to the information being sought, rather than having to visit every server on a network. Weider says the architecture, which supports parallel searches, should be able to speed the delivery of search results since, unlike Z39.50, every server does not have to be searched.
People still have problems with Boolean searches.
If this turns out to be more complicated, people will scream a lot, and then, if they are told they have no choice, they simply won't use it. There are also key questions about which architectural approaches will win out in the marketplace. Weider, for example, admits that Bunyip's approach overlaps with the Harvest approach, which is already being deployed on the Internet. Harvest, h e says, also has tools to make it easier to pull information out of files automatically to create an index. But Weider's feeling is that humans will have to become involved in indexing at some point because the kind of tools needed to truly do that job well would require a semantic understanding close to human intelligence.