Evaluating Sources of Information

Why Evaluate?

Once you have found information that matches the topic and requirements of your research, you should analyze or evaluate these information sources. Evaluating information encourages you to think critically about the reliability, validity, accuracy, authority, timeliness, point of view or bias of information sources.
Just because a book, article, or Web document matches your search criteria and thus seems, at face value, to be relevant to your research, does not mean that it is necessarily a reliable source of information.

It is important to remember that sources of information comprising the Library's print and electronic collections have already been evaluated for inclusion among the Library's resources. However, this does not necessarily mean that these sources are relevant to your research

This does not necessarily apply to sources of information on the Web for the general public. Many of us with Internet/Web accounts are potential publishers of Web documents; most of this content is published without editorial review. Think about it. Many resources are available to help with evaluating web pages.

Questions to Ask

What criteria should you use to judge information sources?

Initially, look at the author, title, publisher, and date of publication. This information can be found in the bibliographic citation and can be determined even before you have the physical item in hand.

Next, look at the content, e.g. intended audience, objectiveness of the writing, coverage, writing style, and, if available, evaluative reviews.

The following questions should be asked:

Who is the author (may be individual or organization) and/or publisher?

What are the credentials and affiliation or sponsorship of any named individuals or organizations?
How objective, reliable, and authoritative are they?
Have they written other articles or books?
Is the author(s) listed with contact information (street address, e-mail)?
Has the publisher published other works?
Do they specialize in publishing certain topics or fields?
Is the publisher scholarly (university press, scholarly associations)? Commercial? Government agency? Self (“vanity”) press?

What can be said about the content, context, style, structure, completeness and accuracy of the information provided by the source?

Are any conclusions offered? If so, based on what evidence and supported by what primary and secondary documentation?
What is implied by the content?
Are diverse perspectives represented?
Is the content relevant to your information needs?

When was the information published?

Publication date is generally located on the title page or on the reverse side of the title page (copyright date).
Is the information provided by the source in its original form or has it been revised to reflect changes in knowledge?
Is this information timely and is it updated regularly?

Where else can the information provided by the source be found?

Is this information authentic?
Is this information unique or has it been copied?

Why was the information provided by the source published?

What are the perspectives, opinions, assumptions and biases of whoever is responsible for this information?
Who is the intended audience?
Is anything being sold?

Where to Look for Answers

Books and Articles

An initial evaluation of books and articles can be done by examining their bibliographic citations provided in library catalogs (such as the PAC) or periodical indexes and databases, containing brief author, publisher and date of publication information. Once you have found the book or article, look for additional information about the author(s) or publisher. If little or no biographical information is provided about the author(s), ask a reference librarian for Research Assistance.

The librarian may also be able to help you find book reviews.

Web Documents

Ideally, Web documents will include the following elements which can be used in the evaluation process:

Author or contact person with addresses (street, e-mail)
Document Uniform Resource Locator (URL), including an institutional identifier (e.g., an edu with a URL identifies the sponsoring institution as an educational institution)
Date of creation or revision
Link to sponsoring institution Web site

For more information on evaluating Web documents, see:

For exercises in evaluating Web documents, see Evaluating Sources of Information: Sample Web Documents.

Evaluation Resources

Help evaluating Web documents is provided by the following authors. In addition to Evaluating Sources of Information: Sample Web Documents, examples of Web documents for evaluation are provided by Alexander and Tate, Beck, Grassian, Henderson, Jacobson and Cohen, and Lesley University.

Jan Alexander and Marsha Tate, Widener University, provide Evaluation Checklists for advocacy, business/marketing, news, informational, and personal home Web documents. See Actual Web Pages as Examples.
Susan Beck, New Mexico State University, lists major Evaluation Criteria. See Examples.
Esther Grassian, UCLA College Library, lists many points to consider when Thinking Critically about World Wide Web Resources. See Hoax? Scholarly Research? Personal Opinion? You Decide! for examples. See also Who Dunnit: What Kind of Web Page Is This??
Robert Harris, Southern California College, provides a checklist for information quality when Evaluating Internet Research Sources.
John R. Henderson, Ithaca College, provides six suggestions when looking at Web pages in his ICYouSee guide to critical thinking about the Web. See the pop quiz and one more st*p*d assignment for examples.
Trudi E. Jacobson and Laura B. Cohen, University at Albany, devised their own fake Web site in association with their Teaching Students to Evaluate Internet Sites Web site.
Lesley University has a Web page that provides criteria for Evaluating Web Sites, as well as example Web sites.
Joan Ormondroyd, Michael Engle and Tony Cosgrave, Cornell University, offer general suggestions on How to Critically Analyze Information Sources.
Betsy Richmond, University of Wisconsin-Eau Claire, lists Ten C's for Evaluating Internet Resources.
Hope N. Tillman, Babson College, addresses issues related to Evaluating Quality on the Net.
The University of California, Berkeley, Library provides information on Evaluating Web Pages: Why and How

Additional resources, in print and electronic format, on evaluating Web documents are listed at the following Web sites:

Dr. T.Matthew Ciolek's and Irena M. Goltz's Information Quality WWW Virtual Library, and
Nicole Auer's Bibliography on Evaluating Internet Resources.