Access to relevant information is one of the most important requirements of all human endeavours. This need has been recognized and has resulted in the continuing effort to describe and organize information so as to facilitate its expected discovery and ready access. An increasing number of research institutes, universities and business organizations are currently providing their reports, articles, catalogs and other information resources on the Internet in general and the Web[BERN, BERN3] in particular. This is now becoming the accepted method of disseminating and sharing information resources in hypermedia. At this time a number of information sources, both public (free) and private (available for a fee), are available on the Internet. They include: text, computer programs, books, electronic journals, newspapers, organizational local and national directories of various types, sound and voice recordings, images, video clips and scientific data. Also, private information services such as price lists and quotations, databases of products and services, and speciality newsletters are available.
A number of index generation systems and related search systems are currently available on the Internet[DEBR, EMTA, FLET, KAHL, KOST, MAUL, MCBR, SEAR, THAU, WEBC, WWWW, YAHO]. Some of these are manually generated indices(Aliweb[KOST], CUI W3 Catalog[WWWC], GNA Meta-Library[GNAM], DA-CLOD[DACL]) while others are generated by robots (Harvest[HARV], Lycos[MAUL], Nikos[NIKO], Yahoo[YAHO], Web Crawler[WEBC]). Some of these are specialized for the Web, others are for locating files on Anonymous FTP sites. The search interface provides users very little flexibility and the results obtained are varied. This is illustrated in Table 1 for a query using the first and last names of the author as the search term. Even Lycos which claims to have indexed nearly 4 million documents has only partial success in locating all relevant documents[DESA4][3] July 24, 1995.
+--------------+----------+-----------+----------+---------+
| Search | Number of| Number of | Number of| Number |
| System | Hits | Duplicates| Mis-hits | missed |
+--------------+----------+-----------+----------+---------+
| Aliweb | none | - | - | 24 |
+--------------+----------+-----------+----------+---------+
| DA-CLOD | none | - | - | 24 |
+--------------+----------+-----------+----------+---------+
| EINet | 6 | 0 | 4 | 22 |
+--------------+----------+-----------+----------+---------+
| GNA Meta Lib.| none | - | - | 24 |
+--------------+----------+-----------+----------+---------+
| Harvest | none | - | - | 24 |
+--------------+----------+-----------+----------+---------+
| InfoSeek | 7 | 0 | 0 | 17 |
+--------------+----------+-----------+----------+---------+
| Lycos | 231 | 2 | 222 | 17 |
+--------------+----------+-----------+----------+---------+
| Nikos | none | - | - | 24 |
+--------------+----------+-----------+----------+---------+
| RBSE | 8 | - | 8 | 24 |
+--------------+----------+-----------+----------+---------+
| W3 Catalog | none | - | - | 24 |
+--------------+----------+-----------+----------+---------+
| WebCrawler | 7 | 3 | 0 | 20 |
+--------------+----------+-----------+----------+---------+
| WWWW | 2 | 0 | 0 | 22 |
+--------------+----------+-----------+----------+---------+
| Yahoo | none | - | - | 24 |
+--------------+----------+-----------+----------+---------+
Table 1 Search statistics for using the search term Bipin (AND) Desai