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Google only searches 1% of the data, use the invisible web to search the other 99% of data

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  1. 1. Michelle Post, Ph.D.
  2. 2.  What is it? Visible vs. Invisible How does it work? How big is it? Where is it going? Invisible Web Search Engines Invisible Web Databases Video Training Resources References © Michelle Post, Ph.D. 2
  3. 3.  “Searching on the Internet today can be compared to dragging a net across the surface of the ocean. While a great deal may be caught in the net, there is still a wealth of information that is deep, and therefore, missed. The reason is simple: Most of the Webs information is buried far down on dynamically generated sites, and standard search engines never find it” (Bergman, 2001, para. 2). “The "visible web" is what you can find using general web search engines. Its also what you see in almost all subject directories. The "invisible web" is what you cannot find using these types of tools” (UC Berkeley Library, n.d., para. 1). © Michelle Post, Ph.D. 3
  4. 4.  “The deep Web contains 99% of the information content of the Web; however, most of this information is contained in databases and is not indexed by search engines” (Gruchawaka, 2010, para. 1). “If the most coveted commodity of the Information Age is indeed information, then the value of deep Web content is immeasurable” (Bergman, 2001, para. 5). Michelle Post, Ph.D. 4
  5. 5. Surface Web Deep WebMillions of web pages Over 200,000 databases1 billion documents 550 billion documents19 terabytes 7,750 terabytesBroad shallow coverage Deep vertical coverageResults contain ads Results contain no adsContent unevaluated Content evaluated by experts(Bergman, 2001) © Michelle Post, Ph.D. 5
  6. 6.  “The deep Web is qualitatively different from the surface Web. Deep Web sources store their content in searchable databases that only produce results dynamically in response to a direct request” (Bergman, 2001, para. 4). © Michelle Post, Ph.D. 6
  7. 7.  Public information on the Deep Web is currently 400 to 550 times larger than the commonly defined World Wide Web. The Deep Web contains 7,500 terabytes of information, compared to 19 terabytes of information in the surface Web. The Deep Web contains nearly 550 billion individual documents compared to the 1 billion of the surface Web. More than an estimated 200,000 Deep Web sites presently exist. Sixty of the largest Deep Web sites collectively contain about 750 terabytes of information – sufficient by themselves to exceed the size of the surface Web by 40 times. (CompletePlanet, n.d., para. 6) Michelle Post, Ph.D. 7
  8. 8.  “The deep Web is the fastest growing sector of the Web and it appears to be the „paradigm for the next generation Internet‟” (BrightPlanet, 2005, para. 35). © Michelle Post, Ph.D. 8
  9. 9.  ResourceShelf - Direct Search - Complete Planet - Michelle Post, Ph.D. 9
  10. 10.  Listing of Largest Deep Web Sites - engines/help/largest_engines.jsp Directory of Open Access Journals - Educators Reference Desk - Find Articles - On-Line Encyclopedia of Integer Sequences - PubMed - Super Searchers Web Page - Michelle Post, Ph.D. 10
  11. 11.  The Virtual Private Library and Deep Web - he-virtual-private-library-and-dee_news Michelle Post, Ph.D. 11
  12. 12. 100 Time-Saving Search Engines for Serious Scholars - time-saving-search-engines-for-serious-scholars/Deep Web FAQ - engines/help/help_deepwebfaqs.jspThe Invisible Web Databases - n/5locate/advicedepth.htmlThose Dark Hiding Places: The Invisible Web Revealed - b.htmlWhite Paper: The Deep Web: Surfacing Hidden Value - idx?c=jep;view=text;rgn=main;idno=3336451.0007.104 Michelle Post, Ph.D. 12
  13. 13. Bergman, M. (2001, August). White Paper: The deep web: Surfacing hidden value. The Journal of Electronic Publishing, 7(1), doi: 10.3998/3336451.0007.104. Retrieved from idx?c=jep;view=text;rgn=main;idno=3336451.0007.104BrightPlanet. (2005). Deep webfaq. Retrieved from (n.d.). How large is the deep web. Retrieved from engines/help/help_deepwebfaqs.jspGruchawka, S. (2010). Using the deep web. Retrieved from Berkeley. (n.d.). Invisible or deep web: What it is, how to find it, and Its inherent ambiguity. Retrieved from bleWeb.html © Michelle Post, Ph.D. 13