Wide Area Information service (WASI) Engine:
The Wide Area Information Service or WASI enables user to search the contents of files for any string of text that they supply. An extremely versatile service, WASI uses an English language query front end to a large assortment of databases that contain text based documents. What does WASI do? WASI lets users search the full text of all the documents on a server.

Users on different platform can access personal, company and published information from the one interface-text, pictures, voice or formatted documents. Since the system uses a single computer to computer protocol, information can be stored anywhere on different types of machines. Any one can use this system because it uses natural language questions to find relevant documents. Relevant documents can be fed back to a server to refine the search. Successful searches can be run automatically to alert the user when new information becomes available. How does WASI work?

The servers take a user question and do their best to find relevant documents. The user then enters query, which can be a list of keywords such as x.500 and directory or even a sentence in plain English, such as what musical instruments do west Indian use? After inputting the search string and the target database the user specifies the maximum number of hits WASI can return for a given query(this step saves valuable time and bandwidth)

The WASI servers at this point do not understand the users English language question rather they try to find documents that contain those words and phrases and key words. Each documents title contain a score, from 1to 1000 indicating how often WASI found the search terms in the documents. At the point in the session, the user can reeter a more specific query retrieving one of the documents or mark the documents that have similar content(phrases in headings, title and text).

The WASI client interface has changed tremendously in the last few years. Today the Netscape or NCSA-Mosaic browser with the forms capability is often used as a front-end to talk to a WASI server. The advantages of this approach is the familiarity of the interface and ease of use. Technically WASI has three elements, a client a server and an indexer. here’s how the pieces work together. First, the indexer takes a list of files the publisher wants to index and generates from it several index files.

The indexes include a directory of all words appearing in the databases, a list of documents and files that constitute the databases and the “headline” of the documents contained in the database(a short summary for users who search the database). With the index created the user must tell the rest of the world about it. The publisher does so automatically by owning WASI with a register option which places this index next to the hundreds of WASI indexes already available on the internet items such as a legal index from west publishing, indexes of government documents and countless academic databases. When users search through the centralized directory of servers they will be linked to this index automatically.

WASI solves a number of problems from the users perspective. First, it allows user to identify and select information from large databases. Second it provides heterogeneous databases, may be on a variety of different systems and the user need not know how to use each system. Finally it provides ways to download and organize the retrieved data so that users are not overwhelmed.

Today both commercial versions and freeware server versions (known as free WASI) are available. The European Microsoft Windows NT Academic center (EMWAC) has ported Unix-based free WASI to the Windows NT platform. The newest release WASI server 2.0 builds on WASI by adding incremental indexing which spares large databases publishers from re indexing an entire database after it is amended. It also integrates WASI gate, Which lets WASI receive search requests from many more clients.

How is WASI used? Some publishers create the WASI indexes of files that they serve through the World Wide Web or gopher. These indexes enable users to search the contents of those files. Several companies use WASI to sell information over the internet. One can associate a cost directly with WASI sources unlike many other internet services. Some sources for examples, share a certain amount for each document which others charge an hourly rate to search them and an additional fee for the documents themselves.

Incoming search terms:

• explain wais