This page explains how to apply the RADAR criteria for evaluating sources to books.


  • Was your book written to educate, inform or entertain? Entertainment books can have useful information but may not be up to academic standards.
  • Does the text show a bias? Is it trying to persuade the reader? A bias may be useful if your paper needs to include various viewpoints on a topic.
  • Read the preface and introduction to find out what the authors of the book are trying to accomplish with their work.


  • Check for information about the authors at the end of the book or on the back cover. You could also try entering their names in an online search engine.
  • What are the authors’ credentials? Are they journalists, experts in the field, or do they hold a Master’s or PhD degree? Are they associated with a university or organization?
  • Do you think their credentials are sufficient for them to be qualified to talk about this topic in particular?


  • Do you need the most recent information possible for your assignment? For an ancient history project, the currency of your sources may not be as important as it would be for a paper on digital technology.
  • Keep in mind that publishing a book takes time and that the most recent book on your topic may not have this year’s date.
  • When was the book published? Look for the copyright date on the verso of the title page.
  • How recent are the references cited by the author? You’ll find these in the notesbibliography or references section.


  • Check for in-text citations or footnotes. Is there a list of notes, references or a bibliography in your book?
  • Have you seen this information in a different source during your research? Does the text agree in general with these other sources?
  • Does the text contain any statements you know to be false? If so, this could make you question the veracity of the statements you aren’t familiar with.
  • Are there many spelling or grammar errors in the text? Too many errors could lead you to doubt the quality of the information.


  • Make sure that your source is relevant to your research before using it.
  • Books can cover a lot of ground and they tend to be more general in their scope. As such, you won’t always find whole books on your topic. It’s ok to only use part of a book, like a specific chapter or a paragraph that relates to your subject.