andreas.com FAQ: The Invisible Web
The “invisible web” is the part of the web that most search engines don’t reach. If you are looking for special or specific information, you can find it in the invisible web.
- The Surface Web: This is the general web that’s indexed by Yahoo, Altavista, and Google. These are mostly websites.
- The Invisible Web: The contents of thousands of research libraries, government databases, and so on.
The Invisible Web is…
- Over 100,000 invisible websites.
- Contains PDF files and specialized databases
- 500 times larger than the visible web
- 750 times larger than the Library of Congress
- 550 billion documents (The visible web has only 1.5 billion documents.)
Portals to the Invisible Web
With Yahoo, you find a thing. With these portals, you first find a database, and then you drill down and find specific information.
- Lycos Collection (with comments)
Search Engine of the Invisible Web
- ProFusion from Intelliseek searches over a thousand databases in the Invisible Web.
For example, you can search multiple job databases to find a job. Go to ProFusion, click Careers, select High-Tech Jobs and search within the category. Click [all] to search all databases, type your job description and city, such as [junior technical writer in San Francisco], and press Enter.