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Think you're getting all the information available when you browse the Web with your favorite search engine? Chances are that, amid a pile of unproductive links and ads, you're only scratching the surface when it comes to getting the content you need. There may be hundreds of additional resources available to you, but they're invisible to the traditional search methods employed by many search engines. This is why researchers refer to the many "hidden" online databases and dynamic query pages as the invisible Web. If you've ever browsed a data repository at your local library, searched for jobs online, or even visited Amazon.com to do some shopping, you've dipped into the invisible Web. In this article, we'll dispel the mystery surrounding the invisible Web and, by changing the way you search, put a number of new resources at your disposal you might not have thought existed.
If it's invisible, how do I see it?
The invisible Web, sometimes called the deep Web, isn't really invisible, but typically represents content deeper and narrower in nature than the more easily accessed, visible Web sites. Image directories, abstracts, government documents, and resource repositories like physician listings are common examples of files likely to be stored in the hard-to-find databases that constitute the invisible Web. Before we explore its nature and how you can extract information from the databases and dynamic pages inhabiting it, we'll explain why it's hidden apart from the visible Web. Then, we'll look at how to modify your search criteria to give your research the depth it deserves. We'll also introduce you to three sites geared toward traveling down those Internet back alleys. Finally, we'll point you to additional resources to help you tap the invisible Web no matter where your interests lie.
How Web pages disappear
The Web is much more than static pages these days, moving rapidly from a network of HTML-based documents to a warehouse of multimedia resources, user-driven Web pages, and various programming technologies. To give you some context,...