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Research 101

How to Evaluate Sources

As the amount of published information continues to grow exponentially, it is important to think critically and evaluate your sources. Content is published by individuals, organizations, businesses, governments, and countries. Note that there is no automatic formal review of some published content. While the content on the Ithaca College Library's website and in our print, media, and online collections has been selected by professional librarians, other content may be published and/or posted on the Web by non-experts. The ability to evaluate the information you find is a key critical thinking skill.

While there are many criteria that you can use to judge a source, we recommend looking at Author, Review, Date, Bias, and Sources. Below you'll find more information on how to evaluate using those criteria.



When you're looking at a source, pay attention to who wrote it. Are they qualified to write about this issue? Should you trust them? You should check the authors of books and articles, but this is especially important when you're looking at blogs and websites. Here are some things to consider:

  • Is the author who they say they are? See if you can verify their credentials (are they a doctor, professor, or professional in their field?). 
  • For websites, what kind is it (.org, .edu, .gov, etc)? Is more information about the group available?
  • Is an organization or group listed as the author? If so, what are their credentials? Do they list them?  



Books, articles, and newspapers all undergo some form of review process. Scholarly books and articles will be reviewed by editors and experts in the field to check for accuracy and to assess the research methodology. Newspapers are reviewed by an editor. However, many sources you can find online have not had any review. Blogs, websites, podcasts, and other online sources are easily self-published. That means that there has been no one to check if the information is accurate. Here are some things you'll want to consider when looking at a source:

  • Has the information been reviewed? Was it published in a journal or by a reputable publisher?
  • Can you get more information about the publisher? For example, for a journal, can you check their website to see who runs the journal? Are they affiliated with a college/university or professional association?


The currency of information is essential for some types of research and less so for others. Historical information that reflects people and events that have occurred in the past is relevant to historical research in many fields. In other fields such as health care, legislation, and finance, current information is used in research. Here are some things to consider:

  • When was the information published or last updated?
  • Have newer articles been published on your topic?
  • Are links or references to other sources up to date?  Do the links work?
  • Is your topic in an area that changes rapidly or will older sources work as well?

Check the bottom of a webpage for the publication date, copyright date, or date last updated information. The copyright information for physical materials is listed in the catalog record and/or the bibliographic information.


Scholarly sources will always list the sources used, generally in the form of a bibliography. Other information types, like websites and blogs, might list sources but may not. You should always be skeptical of information that doesn't list a source, since you don't know where the information came from. When you review sources, check:

  • Does the author cite the work of others?
  • Are the sources listed in the bibliography or links related to the topic of the original source?
  • What kinds of sources are listed?
  • For online sites, are the links current or are they dead ends?


All information can have bias - being aware of what a source is trying to convince you of and why can help you decide whether it is trustworthy or useful. To evaluate the bias of a source consider:

  • What is the intent of the source? Does it want to persuade you? Does it want you to buy something?
  • For websites, are there ads? How to they relate to the topic of the site?
  • Is the author presenting fact or opinion?
  • Is the language used impartial?


Which Search Tool When

  • Web search: Use to verify quick facts and find general websites.

Take the Quiz

Want to test your ability to evaluate sources? Read this guide then take the quiz!

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