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The deep web includes content in searchable databases available to web users but not accessible by popular search engines. This video provides an introduction to the deep web search engine and how it can be used to access research and development information contained in previously hard-to-find databases.
Size estimates from Google.com, Yahoo.com, Cyberatlas, and MIT. These stats are current to Spring 2010:
From about.com, What is the 'Invisible Web'? by Paul Gil
Google, MSN and Yahoo only access the top 20% of the information available on the web - the remainder is either hidden but freely available with the right search tools, or it is locked behind password-protected websites - eg our school databases.
If you learn to use some of the search tools mentioned below, you will be able to access a lot more high-quality information.
Image from http://www.juanico.co.il/index.html
Follow these links for more information:
There are a lot of different search tools freely available to help you access the Deep Web.
Don't be put off by the number of different ones available - read about them and try a few different ones.
Information from WikiHow
Useful Tools for Accessing the Deep Web :
CompletePlanetTM uses a query based engine to index 70,000+ deep Web databases and surface Web sites. Appendix A lists 60 of the largest deep Web databases which contain 10% of the information in the deep Web, or 40 times the content of the entire surface Web. These 60 databases are included in CompletePlanets indexes. CompletePlanet is sponsored by BrightPlanet® Corporation, a leader in deep Web searches. The interface is intuitive and easy to use. You can do a keyword search on all 70,000+ databases to find which databases to use for your search. You can also browse by category, and then search databases of interest.
With an account, you can setup custom My Search Groups to search customized lists of websites and/or databases of your choice. For example, you could create a group called Technology and add all the databases and websites of interest to you. This group is saved to your profile. You could then, at any future time, search this group on a research topic with keywords. This is a great time saver. Their query based engine is called SmartDiscovery®.is a combination of query based engine and a deep Web directory portal. The directory structure is accessed by clicking on Specialized Searches.
a site's existing search capability as part of the meta-search process to tap the deep Web. They use proprietary algorithms to interpret the site's search criteria (Boolean, etc). With an account, you can also setup custom SearchSets to search customized lists of websites and/or databases of your choice. Surfwax also has a news accumulator feature with over 50,000 news topics in 84 categories. This news accumulator feature is a godsend providing high quality results. These are some useful news accumulator categories: all topics, networking, technology, telecommunication, and web services. In addition this site has WikiWax which takes the online encyclopedia Wikipedia to the next level. WikiWax does advanced look-aheads on Wikipedia searches to speed your keyword choices.also uses
Information from http://techdeepweb.com/4.html