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HIS 270 - American Environmental History

The guide provides resources relevant to the history of the American environment, paying particular attention to the impact of European settlement on the landscape and the subsequent commodification of resources that defined the American experience.

Evaluating Sources - Two popular methods

The C.R.A.A.P.O Method

One useful way to evaluate your sources is to use the C.R.A.A.P.O. test. C.R.A.A.P.O. is an acronym to help you remember the primary criteria for evaluation: Currency, Relevancy, Accuracy, Authority, Purpose, Objectivity.

Here are some quick tips to help you locate the information you need to evaluate the source under these criteria:

  • Currency: Is the content presented current enough for your project? Some research topics, such as those in the medical field, may require very current resources, but for others, such as historical research, older material may be well-suited. Look for the publication date of the article or resource. If it is a journal article found through the library's website, the publication date will be included in the journal publication information along with the volume and issue number.
  • Relevancy: Does it answer your question or contribute to your research? Have you located the most relevant resources for your project? You may need to look past the first page of search results to find relevant resources. For articles and resources found through the library's website, look at the abstract, summary, table of contents, and subject terms to help you determine if the source is relevant to your research.
  • Accuracy: Is the information provided correct? Peer-reviewed journal articles go through an additional vetting process by experts in the field before they are published, but not all journal articles are subject to this additional layer of verification. Credible resources usually give references for facts and statements made within them. For articles and resources found through the library's website, look at the bibliography or reference list (if available). You can also find out more about the publisher or journal through their official website or through information provided within the source.
  • Authority: Does the author have expertise on the topic about which he/she is writing? You will need to find some basic information about the author in order to determine their level of authority with your topic. Depending on the type of resource you are using (newspaper article, website, journal article, etc), you may have the best luck finding information about the author through a general internet search. For more tips, check out our FAQ: How can I find information about an author?
  • Purpose or Objectivity: Is there bias or a slant given to the information provided? Is it fact-based or opinion-based? Look through the full text of the source for facts, opinions, statistics, advertisements, and other clues. Look up the author and the publisher and see what their affiliations are, and check out other material published by that author or publisher.


For a full description of each criteria and additional tips for evaluating websites, check out our Evaluating Sources research guide.

The S.I.F.T. Method

The S.I.F.T. method offers a more active form of evaluating a source. S.I.F.T. stands for, Stop and reflect, Investigate the source, Find out if the claim is mentioned in other sources, and Trace the claim or quote back to the original source. You may employ the C.R.A.A.P.O criteria during step two of the S.I.F.T. process, Investigate.



  • Does the content of this article elicit an emotional response in you?
    • Yes? The content probably carries a bias.
    • No? Continue!

Investigate the source (see if any of the C.R.A.A.P.O criteria are appropriate)

  • What do you already know about the website this article comes from?
    • It's a reliable, trusted news source-go ahead and read the article.
    • Don't know? Keep sifting...
  • Who wrote it?
    • Would you consider them an authority on the topic?
      • Yes? Go ahead and read the article!
      • No? Keep sifting...

Find trusted coverage

  • Are there other articles that support and affirm the information in this article?
    • Yes! Bookmark them all-you will need them later.
    • No? Toss it and move along.

Trace claims, quotes and media back to the original context

  • Is the article, video, research or image you're looking at original or reposted?
    • No? Track down the original source (or sources)!
    • Yes? Go ahead and read or watch the resource and gather information.
  • Is what your looking at the entire work, video, research study or is it an edited version?
    • No? Track down the original source (or sources)!
    • Yes? Go ahead and read or watch the resource and gather information.