Now that you've found sources on your topic, you need to evaluate how relevant and reliable they are. Not everything that has been published is accurate or reliable … shocking, but true. This is especially true for things you find on the Internet. Here are some general rules to assess the reliability of the sources you are using:

What does it cover?

• How relevant is it to your topic? Remember that sources not specifically on your topic can still provide relevant related information. Read abstracts of the publication, or scan introductions, tables of contents, and indexes for a quick overview of its contents.
• Does it provide any new information? It does not have to be newly discovered information; as long as it is new to you, it can be useful to your research. Even repetition of what you have already turned up in your research can help to confirm or deny the accuracy of those findings.

Who is the author?

• What are the author's qualifications for writing on this subject?
• Is the author a respected scholar in the field? Have you read or heard the author's name from your professor, in class readings, in subject encyclopedias? Is the author frequently cited by other scholars in the field?
• Is the author affiliated with an institution or organization? If so, what are the purposes and goals of the institution?

  For more information on an author, ask your professor, or look in Contemporary Authors, Who's Who in America, Biography Index, and other biographical reference sources. You can also check a Citation Index to see whether other scholars have cited this author in their publications.

What is the author's purpose?

• Is it an opinion piece designed to persuade readers, or is it intended to be an objective examination or presentation of information?
• Does the author have a bias? If so, does the author state and discuss it explicitly, or give reasons to defend it?

Type of source

• Books can provide broad and thorough coverage of a range of related topics. You can often find reviews of books (in subject specific indexes or Book Review Index) which critique a book's value; try to find a few reviews and see whether the reviewers agree on the merits of the book and its author.
• Journal articles are more narrowly focused, but can be published quickly to provide more up to date information. See the page on different types of journals for more specifics on evaluating journals.
• Reference works (encyclopedias, almanacs, etc.) provide brief introductory or summary information, and may list other sources of more extensive information.
• Audio and visual recordings, diaries, letters, business records, lab reports, and many other sources, published or unpublished, can offer useful information depending on your research needs. Think very broadly about the possibilities for sources for your research.

Who published it?

• Is it a university press? If not, does the publisher print many academic titles? What is the publisher's reputation?
• Why did this publisher publish this source?
• Did editors and fact checkers assess the accuracy of the information before it was published?

When was it published?

• Is the information current enough for your needs? Knowledge in the sciences develops and accumulates very quickly, and scientific research requires current information. Humanities research is not as time-sensitive.
• Is there a revised or updated edition? Newer editions typically contain revisions to correct errors or omissions in the first edition, or include updates of recent changes and developments in the field.

Who is the intended audience?

• Is it intended for specialists in the field? If you are doing general level research, it may be too technical or detailed for your needs.
• Is it too general or too basic for your needs? A high school textbook may be accurate, but not advanced enough for college level research.

How does it compare with other sources?

• Does it match what you have learned so far in your research? If information you have already learned and verified elsewhere is accurately presented, it is more likely to be reliable when it discusses issues new to you.

Has it been reviewed or cited by others?

• Have other scholars in the field reviewed or commented on it favorably? Look for book reviews in Book Review Index, subject specific indexes, or Web review sites, or search in a Citation Index to see who has cited it as a source.

Additional Considerations for Internet Sources:

• Domain - Look at the URL (uniform resource locator, or site address. e.g. "http://www.wesleyan.edu/file/folder/document.html") to see the type of site. Some of the most common are:
  • edu - education - Is it an "official" college or departmental page, or a student's personal page?
  • gov - government - Which department, agency, etc, is responsible for the page?
  • com - commercial - Includes news sources, but also includes companies' information and marketing pages: what is the purpose of the page?
  • org - organization - Includes many advocacy groups: what is the purpose of the page?
• Personal or "official" - The contents of a personal home page are not necessarily endorsed by an institution. A personal home page will often have a "~" in the URL.
• Maintenance - Who maintains the page, and how up-to-date is it? Does it indicate when it was most recently updated?
• Stability of the site and its contents - Web pages, especially personal pages, can come and go or be changed easily and frequently.
• Software and hardware requirements - Does the site have features that require specific software or hardware to access? Can you access everything the site offers?
• Links - If the page links to other sites, check them out … sometimes links from personal sites which contain dubious information will take you to official sites with more reliable content. (But sometimes not … remember to evaluate the linked sites using these same ideas!)

Additional Reading:

Here are a few sites that discuss the issue of evaluating information sources, with a particular emphasis on Internet resources:

• How to Critically Analyze Information Sources from the Cornell University Library System
• Resource Selection and Information Evaluation from a reference librarian at Parkland College Library
• Evaluating Quality on the Net a paper presented by Hope N. Tillman at Computers in Libraries, 1996, updated May 2000.