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Rosen Research Guides

Evaluating Internet Sources
and Using the "Deep Web"

Ask a Rosen Librarian!

Tim Bottorff
Department Head


This guide is designed to help you evaluate the quality of information found on the World Wide Web and to lead you to the best resources available through the Internet. For more assistance, please Ask a Rosen Librarian.

A shorter, printable version of this guide is also available: Evaluating Internet Sources PDF (45 KB).

Surfer Beware!

Information on almost any topic can seemingly be quickly and easily accessed on the World Wide Web.   However, you must be very careful about using such information for academic research.  Keep in mind that anyone with the right combination of hardware/software skills can place any information they want on the World Wide Web. In addition, there is usually no one editing or fact-checking the material placed online, as there is for more traditional sources such as books and journal articles.

In approaching information published for free on the World Wide Web, one way to evaluate the quality of information is to use the CARS criteria: Credibility, Accuracy, Reasonableness, and Support:


  • Is the author listed? Are the author's credentials listed? Is the author a known or respected authority on the subject?
  • Does the source have organizational support? If so, is the organization well-respected?
  • Does the URL end with .gov, .mil, .edu, or .org?
  • Is there evidence of quality control? Does the author use proper spelling and good grammar?


  • Is the information in the source current? Does the site indicate when the document was created or when it was last updated?
  • Is the information factual, detailed, exact?
  • Does the author strive for completeness and accuracy?
  • Is the information in the source geared to your level of understanding?


  • Does the information presented seem balanced, objective, reasoned?
  • Is there an obvious conflict of interest? Does the author or supporting organization seem to give support to any advertisers?
  • Is there a slanted tone? If the source is persuasive, does it back up opinions with facts?


  • Are claims made by the author substantiated with any evidence? For instance, are there bibliographies or footnotes?
  • Does the author provide a way to contact him/her to discuss the information?
  • Is the information given in the source corroborated by other sources?

If a website does not meet most of these criteria, then you should reconsider using that source.

* The CARS method is adapted from Evaluating Internet Research Sources by Robert Harris.

The Surface Web

As you can see, evaluating information published on the World Wide Web can be complex and time-consuming. Occasionally, the effort will payoff and you will find a "gem" of a resource through a well-known Internet search engine (such as Google, Yahoo!, AOL, MSN, etc.). On the other hand, for many academic papers and projects, searching the World Wide Web in this fashion is simply a waste of time.

Fortunately, there are better ways to harness the power of the Internet. When you search the Internet through well-known, commercial Internet search engines, you are mainly searching what researchers call the "Surface Web." The "Deep Web," on the other hand, is made up of all the documents missed by traditional search engines: multimedia files, images, recently-created sites, pages that change dynamically based on user queries, materials in subscription databases, pages that require registration, standard websites that are not "crawled" by the search engines' "spiders," and so on.

The Deep Web: Unlocking the Hidden Power of the Internet

Some of the commercial search engines are starting to develop tools that help researchers unlock the material hidden in the Deep Web.  For example, Google Image Search allows users to find image files, and Altavista allows users to search for audio and video content.

There are also a few search engines devoted to finding Deep Web content on many topics, such as CompletePlanet, Infomine, or Google Scholar .  In addition, there are many specialty search engines, which focus on finding Deep Web content for individual fields of study, such as Scirus for science, and FedStats for government information, and PubMed for medical information.

Keep in mind that information encountered on these sites should generally still be subjected to the CARS criteria above to evaluate their quality. For more assistance with the Deep Web, ask a librarian for help.

Going Even Deeper: Subscription Databases

While specialty search engines can be useful tools to help you uncover Deep Web content, they still do not give you access to all of the content on the Internet. A large portion of the information on the Internet is locked in propriety databases, which are usually accessible only through a registration or a subscription process. In fact, subscriptions to some of these databases can cost thousands of dollars! Moreover, some professors prohibit students from using websites (whether "surface" or "deep") in their research.

Fortunately, you can access these valuable databases, which are essential for doing academic research and accepted by nearly all professors, through something that you already have access to: the UCF Libraries! UCF subscribes to hundreds of these databases and makes them all available to UCF students, staff, and faculty. These databases provide access to journal, magazine, and newspaper articles; statistics; reference works; and many other documents that you cannot find on the Wide World Web. Although evaluating documents found in these databases according to the CARS criteria would still be a good idea, in reality these documents tend to be of a much higher quality than those found on the Surface Web.

These databases can be accessed in any UCF Library, or by using the Library Webpage. For more assistance with using the Library's databases, please refer to the Rosen Research Guide called Finding Articles or ask a librarian for help.

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A printable version of this guide is also available: Evaluating Internet Sources PDF (45 KB)

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Last updated February 03, 2012 1:12:29 PM

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