From the April, 1998 PC ALAMODE Magazine:
Searching for the truth:
how to evaluate 
information sources 
on the Internet
by Michelle Jeske

Unlike most print resources such as magazines, journals and books that go through a reviewing and editing process, information on the Internet is mostly unfiltered. Since the explosion of the World Wide Web (WWW), evaluation of web sites has become much more difficult. The Internet has a lot to offer, but not all sources are equally valuable or reliable. The first thing to determine is whether the Internet is the appropriate source for the task at hand. Quite often, an hour searching the Web may not answer a question that you could find in two minutes using a reference book. On the other hand, the Web can provide current and important information on many topics. 

There are a few questions you can ask yourself that will help you determine if a resource found on the Internet is authoritative. Here is a checklist of points to consider when evaluating any information source.

 Who is the author? Who is the publisher? Does the author have expertise on the subject? Are any credentials or qualifications provided? You should be able to find information about the author, contact person, and/or sponsoring institution somewhere on the web page. If no information is provided on the author, you might consider checking biographical sources on the Internet or at your local library. Check a university or public library's online catalog or periodical indexes to see if the author has written books or journal articles on your topic or any subject. Check biographical sites on the Internet, such as Notable Citizens of Planet Earth ( or ( or use a search engine to look for more information on this person or organization. Ask a reference librarian to help you use Biography and Genealogy Master Index, Biography Index or a subject-specific encyclopedia. 

If you are unable to determine the authority of an individual web page, try manipulating the address to dig deeper into the site. For example, if no sponsoring institution or author information was found at, then, try opening the URL minus the facts.html filename. Type If that doesn't work, try taking off the next element. You can "back-up" the address in this way until you reach the stem address and perhaps find more information there. 

Is the information objective? What is the purpose of the web page? Is there any noticeable bias? Is the main purpose to inform, persuade, or sell you something? Determine whether the source is published by an organization with a particular purpose and attempts to sell a product or promote a particular point of view. Many Internet sources are not reviewed before being posted. Check the URL to see if the domain name includes a .com (commercial), .org (non-profit organization), .gov (government), .edu (educational), .net (network), or a two-letter code for country of origin. The last part of the domain name will indicate some important information about the site, though the domain name alone will not assure the authority of the site. 

The largest growing segment of the WWW is commercial sites. Many offer valuable information about their products or areas of expertise. Much of the information can be helpful and reliable but remember that a company is in business to make money and they do not do that by directing potential customers to other companies' products or services. Not all commercial sites will try to sell you something, but they do warrant a different kind of scrutiny than a governmental site. A good example of a useful and reliable commercial site is Amazon Book Store (, which provides bibliographic citations, comments from authors, professional and amateur reviews AND the opportunity to order books. The commercial label is blurred. The most important thing to pay attention to is whether a site has valuable content and whether its presentation or content biases make any difference in terms of what you need to get out of it. 

Pages found on educational or non-profit organization web sites can be extraordinarily diverse. Educational web sites range from personal home pages (often indicated by a ~ (tilde) in the URL) to cutting-edge articles from top research institutions. Non-profit groups such as the National Rifle Association or the Sierra Club often use the Internet to promote the group's stance on specific issues and often do not provide information or links to differing points of view. Biases may not be explicit and you may have to confirm suspicions by analyzing the point of view of the contents of the site. 

Is the information accurate? Are the facts and statistics verifiable? Does the author provide a bibliography? Look at the end of the source for a bibliography or list of references. Accuracy is not always easy to detect, so you must test one source against another. If possible, all information should be verified in a traditional edited print or electronic source. The information should be replicable. 

Is the information current? How up-to-date are the links? Is currency important to your topic? Look at the date of publication and determine whether it is important to use current sources for your subject. In fields such as medicine and science, currency is important. In fields such as literature and art, older materials may be just as valuable as newer ones. You will usually find the date of creation or revision in the footer of the page. 

At the very least, facts should be accurate and current and the bias and authority of authors clear, but there are other criteria to use when evaluating web sites. Check for the obvious things, such as good grammar and correct spelling. Note the depth of the material presented. When was the item last revised? Do the graphics serve any purpose other than decoration? Do they load quickly? Is there a clear table of contents? The site should be easily navigable. Follow the lead of the editors of the Britannica Internet Guide ( who have reviewed 65,000 sites including only those which meet the following criteria:

  • depth, accuracy, completeness, and utility of information 
  • quality and effectiveness of presentation 
  • credentials and authority of the author or publisher 
  • elegance of design and ease of navigation 
  • frequency of revision 
  • quality of graphics or multimedia
If you are unsure of the validity of a site, try looking for information on your subject using a search engine that includes a section of reviewed sites such as Lycos Top 5% ( or a subject guide created by a specialist such as Company Information on the Web ( There are many sites available where the work has been done for you. Use the San Antonio Public Library's homepage ( for an evaluated and annotated subject directory of Internet resources selected for their usefulness to the public library user's information needs. Many university library web sites provide these kinds of directories as well. 

The most important area to consider when evaluating a web site is content. Try to differentiate fact from opinion. Carefully examine each site and remember that anyone can publish on the Web and you will be fine. 

Michelle Jeske is the Electronic Resources Coordinator of the San Antonio Public Library.