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BIOL 394: Junior Seminar: Types of Sources / Evaluating Sources

Recent advances in biology presented in a seminar format by Redlands faculty, seniors, and visiting scholars.

A Simplified Timeline of Scientific Communication

How can you evaluate and select sources for your research if you don't understand how they differ? Use the following chart to learn more about them.

A simple timeline of scientific communication

Common Questions

Evaluate Your Sources! The CRAAP Test.

Evaluating Information—Applying the CRAAP Test

Printable CRAAP Test

When you search for information you’re going to find lots of it…but is it accurate and reliable? You will have to determine that for yourself, and the CRAAP Test can help. The CRAAP Test is a list of questions you can ask in order to determine if the information you have is reliable. Please keep in mind that the following list of questions is not static or complete. Different criteria will be more or less important depending on your situation or need. So, what are you waiting for? Is your web site credible and useful, or is it a bunch of…?! 
Evaluation Criteria

Currency: Currency is important because information can quickly become obsolete. Supporting your thesis statement with facts that have been superseded by new research or recent events weakens your argument. Of course, not all assignments require the most current information; older materials can provide an historical or comprehensive understanding of your topic. 

How do you know if the timeliness of your information is appropriate?

  • 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?
  • Is your topic in an area that changes rapidly, like technology or popular culture?

Relevance: Relevance is important because you are expected to support your ideas with pertinent information. A source detailing Einstein's marriage and family life would not be germane to his theories in physics.

How do you know if your source is relevant?

  • Does the information answer your research question?
  • Does the information meet the stated requirements of the assignment?
  • Is the information too technical or too simplified for you to use?
  • Does the source add something new to your knowledge of your topic?

AuthorityAuthority is important in judging the credibility of the author's assertions. In a trial regarding DNA evidence, a jury gives far more authority to what a genetics specialist has to say compared to someone off the street.

How do you know if an author is an authority on your topic?

  • What are the author's credentials?
  • Is the author affiliated with an educational institution or prominent organization?
  • Can you find information about the author from reference books or the Internet?
  • Do other books or articles cite the author?

AccuracyAccuracy is important because errors and untruths distort a line of reasoning. When you present inaccurate information, you undermine your own credibility.

How do you know if your source is accurate?

  • Are there statements you know to be false?
  • Are there errors in spelling, punctuation, or grammar?
  • Was the information reviewed by editors or subject experts before it was published?
  • What citations or references support the author’s claims?
  • What do other people have to say about the topic?

PurposePurpose is important because books, articles, and Web pages exist to educate, entertain, or sell a product or point of view. Some sources may be frivolous or commercial in nature, providing inadequate, false, or biased information. Other sources are more ambiguous concerning their partiality. Varied points of view can be valid, as long as they are based upon good reasoning and careful use of evidence.

How do you determine the purpose of your source?

  • Why did the author or publisher make this information available?
  • Is there an obvious bias or prejudice?
  • Are alternative points of view presented?
  • Does the author omit important facts or data that might disprove a claim?
  • Does the author use strong or emotional language?


What kinds of sources might I encounter?

Before you evaluate a source, it helps to know what kind of information source you're looking at. Talk with your advisor about the types of sources you should seek and avoid.


In general books summarize and contexualize original research articles, but aren't considered primary or original research. However, books are sometimes published as collections of original research articles that were published earlier in scholarly journals. Books can help you understand how a research experiment fits within a larger context. Science encyclopedias and dictionaries, written for non-experts, are useful when reading and trying to understand rigorous texts.

News Articles

You're probably pretty familiar with news articles. They tend to be short pieces written by journalists, not physics experts, and report recent developments in the field. You''ll find news articles in popular publications, trade magazines, and scholarly journals. You won't necessarily cite these in your research, but you might use them to learn more about a topic.


You may also be familiar with editorials, or opinion pieces. These tend to be well-researched opinions with or without citations, and can appear in popular publications, trade magazines, and scholarly journals. Since these aren't original research, you might not cite them in your papers, but you could use them to learn about the nuances of a particular experiment or field of research; they might influence the directions you take as a researcher.

Popular Articles

Popular publications like Time magazine and the New York Times publish short articles written by journalists for the general public. You won't cite these in your research but if they parallel specific research articles, they might help you comprehend the scholarly texts.

Trade Magazine Articles

Trade magazines, sometimes called trade journals, find a middle ground between popular publications and scholarly journals. Articles may be longer than those in popular publications, may include a few citations, and do not have the rigor associated with scholarly articles. Readers are professionals in that trade.

Peer-Reviewed Articles

Peer-reviewed articles -- sometimes called research articles, primary research articles, original research articles, and refereed articles  -- are written by and for experts and published in scholarly journals. Unlike popular and trade articles which go through an editorial process, peer-reviewed articles go through a rigorous peer-review process. In short, an author submits an article which is refereed by one, two, three, or sometimes four reviewers. These reviewers are experts in their discipline and peers of the author who is also an expert. Typically the review is "blind" meaning that the identities of authors and reviewers are hidden from one another. These reviewers offer recommendations to the author and may approve or reject an article for publication. Some journals take pride in their high rejection rates.

Review Articles

Review articles, published in scholarly journals, review and summarize developments in a subfield. While readers may be experts in the larger field of physics, they may lack expertise in the subfield and use these reviews to stay informed. Review articles often appear similar to original research articles. To distinguish between the two, you'll need to determine if the authors refer to their own work or if they discuss the research of others.  

Pre-prints & Post-prints

Pre-prints and post-prints refer to scholarly literature before (pre-) peer-review and after (post-) peer-review. Sometimes pre-prints and post-prints are lumped together and considered the unofficial version of a scholarly paper; you can download them from author websites or repositories like arXiv and they'll look like a simple Word document. Although they are unofficial documents that may be riddled with typos, readers value this quick access to new information; the peer review process and publishing both take considerable time.

Conference Proceedings

Conference proceedings are the written versions of research shared at conferences. Experts present their research, and learn from each other at these conferences. Proceedings are sometimes peer-reviewed.

Dissertations & Theses

Dissertations and theses are extensive research projects undertaken while working toward a master's or Ph.D. Although thorough reviews are done by an advisory committee, dissertations and theses do not undergo a formal peer-review process. Although dissertatons and theses may be excellent sources of information, only a few print copies exist and libraries are unlikely to lend them out. They are best obtained through online repositories or directly from the researchers themselves.