The WAIS search engine receives a user’s question, searches its database for documents most relevant to the question, and returns a relevance-ranked list of documents back to the user. Each document is given a score from 1 to 1000, based on how well it matched the user’s question (how many words it contained, their importance in the document, etc.).
The first popular Internet search engine was the Wide Area Information Servers (WAIS) system. The pages linked below describe some of the current leading search sites, including a link to their advanced search page and a feature summary. Most of these sites also provide both a web directory and a search engine:
- Google *
- Yahoo *
Resources. Related resources are listed below:
- Usenet archives – lists sites for searching the Usenet newsgroups.
- Search Engine Sizes – lists the size of leading search engine’s databases.
- Ranking.com – Provides a ranking of web sites by popularity of access, a metric significantly driven by the traffic from leading search engines.
- Specialized search sites provide more targeted search functionality.