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Information Literacy Instruction

Evaluate Information

Critically evaluating all the evidence and sources that you use is a fundamental aspect of all research. You must understand the difference between primary and secondary sources and their uses. You must also know how to distinguish between popular, trade and scholarly or peer-reviewed sources. Once you can do that, just because you found something on the Internet or in a popular source doesn't necessarily mean it can't be used for scholarly research - use the CRAAP test to determine if it is credible and relevant. Just because something was published in a peer-reviewed journal doesn't mean you can't find its weaknesses - deconstruct journal articles to read them critically. Watch this video on evaluating sources and then explore the other tabs on this page to learn more.

Types of sources you will encounter when doing research

You will likely see four different types of information when doing research for your classes:

Popular: Popular articles are typically published in magazines that are for sale in bookstores or supermarket newsstands or, when online, on webpages, blogs or social media. They are written and published quickly by people with little or no expertise or credentials.They rarely contain specialized vocabulary or intent to empirically prove their claims. They are usually not suitable sources for scholarly research, but depending on the context of their use, they might be.

Trade: Trade articles are written by people who are experienced (often very experienced) in their field of employment. They are written for other members of that profession. They often contain specialized vocabulary, appropriate for members of the profession in question. But these articles are written and published quickly in magazines that are sold in popular outlets. They are often not peer-reviewed (see below) and their authors normally do not empirically prove their statements with evidence. Like popular sources, trade articles are usually not suitable sources for scholarly research.

Scholarly: Scholarly materials are written by experts with credentials in their field, typically Ph.D.'s, J.D.'s or M.D.'s. The content and claims in scholarly articles are always supported by primary sources, such as experiments (in the sciences) or diaries (in the humanities). They also often contain detailed analysis of related, previously published secondary sources. These primary and secondary sources are cited in footnotes and a bibliography. A scholarly article is written slowly and requires much research. It is normally published in a journal. Journals are typically only available in universities and libraries.

Peer-reviewed: A peer-reviewed article is a scholarly article that has been evaluated and judged meritorious by other experts in the field. The author of the article submits it for publication and the experts read and evaluate its methodology, analysis and conclusions. Peer review is the most reliable form of scholarship. Journals that contain articles that are evaluated by a board of expert editors are called peer-reviewed journals.

How to Identify Different Types of Periodicals at a Glance

Popular Trade Scholarly
Color covers Plain cover, plain paper (most often)
Glossy papers Glossy papers (Science journals may be glossy)
Ads Ads No ads
Articles on current events Articles on industry trends Primary research, theories, methodologies
General interest Written for members of specific industry Written for researchers & professionals
Short articles Short articles Lengthy, in-depth articles
Informal tone Informal tone Formal and serious tone
Easy to read vocabularies Professional jargons, more difficult to read
Written by general staff Written by staff or experts in the field Written by experts in the field & researchers
Reviewed by general editor Peer review* by subject experts
No bibliographies or footnotes Short or no bibliographies Extensive bibliographies & references
Usually called a "magazine" Referred to as a "journal"; may have "journal" in its name

What are primary and secondary sources?

Your instructor may specify that you should use primary (and/or secondary) sources in your research. What does this mean?

For the humanities, primary sources are contemporary accounts of an event written by someone who experienced or witnessed it. For the physical and social sciences, primary sources may be original research or discoveries.
Primary source may include:
  • Books
  • Photographs and images
  • Magazine and Newspaper Articles
  • Cartoons and Advertisements
  • Diaries and Journals
  • Movies, Videos, DVDs
  • Autobiographies
  • Interviews
  • Public Opinion Polls
  • Letters
  • Speeches
  • Research Data and Statistics
  • Documents produced by organizations
  • Documents produces by Government agencies, for example, congressional hearings and census records

Primary sources may include:

  • Reports of scientific discoveries
  • Results of experiments
  • Results of clinical trials
  • Social and political science research results

Secondary sources interpret, assign value to, conjecture upon, and draw conclusions about the events or results reported in primary sources.

In the humanities, examples of secondary sources include: In the physical and social sciences, examples of secondary sources include:
  • Biographies
  • Histories written by non-contemporary people
  • Literary Criticism
  • Book, Art, and Theater Reviews
  • Newspaper articles that interpret
  • Publications about the significance of research or experiments
  • Analysis of a clinical trial
  • Review of the results of several experiments or trials


Finding primary sources for the humanities

Use the following tips to find primary sources for your humanity classes:

Books from the time period you are researching:  Search the library catalog by topic and limit by date of publication.

Memoirs, letters, interviews, autobiographies, diaries: Search the library catalogs for the name of an individual as an author (last name, first).  If you do not have the name of an individual, search the catalog by subject and add the appropriate subject terms to the subject heading:  Correspondence, Diaries, Interviews, Personal narratives.  (For Example:  subject keywords might be:  japanese americans interviews).  Ask for assistance finding bibliographies and other reference tools that might help you find other materials.

Magazine or journal articles from the time period you are writing about:  Use an article database (such as Academic Search Premier, JSTOR, or Historical Abstracts) to find the citations (title, author, name of the periodical, date, volume, page numbers of relevant articles, or search to find the library location of the periodical title.  Our periodicals are housed downstairs, in our spacesaver shelving.

Newspaper articles from the time period you are researching-for a particular event or date:  Use a newspaper database to locate the citations (title, author, name of the newspaper, date, volume, page numbers) of relevant articles.  You can limit by time period, as well as by subject or keyword.  If you need to determine the dates of events before you search the newspaper database, use a reference material , secondary source or the New York Times Database.

Specific newspaper or magazine title:  Search Lexis-Nexis by magazine or newspaper title.

Records of or materials published by an organization:  Search library catalog, or WorldCat, by the name of the organization as author.

Records of government agencies: Search the library catalog, or Worldcat, by the name of the government agency as organizational author.

Speeches: Search the library catalog by names of authors.  Search the library catalog by subject keywords: -speeches indexes to find reference books that list individual speeches.

Photographs: Search the library catalog by the additional subject terms-photographs or -pictorial works. For example: world war 1939-1945 pictorial works.  Search library catalog by names of persons or topics as subject keywords.  Search an appropriate image database.

Cartoons:  To find books that discuss and reproduce cartoons from a specific time period, search library catalogs by subject and add the subject terms -caricatures and cartoons  For example:  -Spanish-American war caricatures and cartoons.  Search an article database that includes Historical Newspapers, such as the Historical New York Times database.

Identifying Primary Sources in your Library:  Pair the appropriate subject heading with additional subject terms to identify materials as primary sources.  Some of these terms are:  -correspondence, -diaries, -early works to 1800, -interviews, -pamphlets, -periodicals, -personal narratives, -sources. These subject terms will give you a good start on finding primary documents.  For example:  -student movements japan history sources or -france revolution correspondence

How can I be sure the resource I have found is reliable?

To determine if a source that you have found online is reliable, consider the following:

Purpose: How and why the source was created.

• Why does this information exist—to educate, inform, persuade, sell, entertain? Do the authors, publishers, or sponsors state this purpose, or try to disguise it?

• Why was this information published in this particular type of source (book, article, website, blog, etc.)?

• Who is the intended audience—the general public, students, experts?

 Relevance: The value of the source for your needs.

• Is the type of source appropriate for how you plan to use it and for your assignment’s requirements?

• How useful is the information in this source, compared to other sources? Does it answer your question or support your argument? Does it add something new and important to your knowledge of the topic?

How detailed is the information? Is it too general or too specific? Is it too basic or too advanced?

 Objectivity: The reasonableness and completeness of the information.

• Do the authors present the information thoroughly and professionally? Do they use strong, emotional, manipulative, or offensive language?

• Do the authors, publishers, or sponsors have a particular political, ideological, cultural, or religious point of view? Do they acknowledge this point of view, or try to disguise it?

• Does the source present fact or opinion? Is it biased? Does it offer multiple points of view and critique other perspectives respectfully? Does it leave out, or make fun of, important facts or perspectives?

 Verifiability: The accuracy and truthfulness of the information.

• Do the authors support their information with factual evidence? Do they cite or link to other sources? Can you verify the credibility of those sources? Can you find the original source of the information?

• What do experts say about the topic? Can you verify the information in other credible sources?

• Does the source contradict itself, include false statements, or misrepresent other sources?

• Are there errors in spelling, punctuation, or grammar?

 Expertise: The authority of the authors and the source.

• What makes the authors, publishers, or sponsors of the source authorities on the topic? Do they have related education, or personal or professional experience? Are they affiliated with an educational institution or respected organization? Is their expertise acknowledged by other authorities on the topic? Do they provide an important alternative perspective? Do other sources cite this source?

• Has the source been reviewed by an editor or through peer review?

• Does the source provide contact information for the authors, publishers, and/or sponsors?

Newness: The age of the information.

• Is your topic in an area that requires current information (such as science, technology, or current events), or could information found in older sources still be useful and valid? 

• When was the information in the source first published or posted? Are the references/links up to date?

• Are newer sources available that would add important information to your understanding of the topic?

How can I be sure the resource I have found is reliable?

To determine if a source that you have found online is reliable, consider the following:

Currency: the timeliness of the information

  • When was the information published or posted?
  • Has the information been revised or updated?
  • Is the information current or out-of date for your topic?
  • Are the links functional?

Relevance: the importance of the information for your needs

  • Does the information relate to your topic or answer your question?
  • Who is the intended audience?
  • Is the information at an appropriate level (i.e. not too elementary or advanced for your needs)?
  • Have you looked at a variety of sources before determining this is one you will use?
  • Would you be comfortable using this source for a research paper?

Authority: the source of the information

  • Who is the author/publisher/source/sponsor?
  • Are the author's credentials or organizational affiliations given?
  • What are the author's credentials or organizational affiliations given?
  • What are the author's qualifications to write on the topic?
  • Is there contact information, such as a publisher or e-mail address?
  • Does the URL reveal anything about the author or source?

examples: .com (commercial), .edu (educational), .gov (U.S. government), org (nonprofit organization), or .net (network)

Accuracy: the reliability, truthfulness, and correctness of the content

  • Where does the information come from?
  • Is the information supported by evidence?
  • Has the information been reviewed or refereed?
  • Can you verify any of the information in another source or from personal knowledge?
  • Does the language or tone seem biased and free of emotion?
  • Are there spelling, grammar, or other typographical errors?

Purpose: the reason the information exists

  • What is the purpose of the information? to inform? teach? sell? entertain? persuade?
  • Do the authors/sponsors make their intentions or purpose clear?
  • Is the information fact? opinion? propaganda?
  • Does the point of view appear objective and impartial?
  • Are there political, ideological, cultural, religious, institutional, or personal biases?

Note: all credit for the CRAAP test goes to the librarians who developed it at CSU Chico.

Characteristics of reliable, non-scholarly sources

Characteristics of valuable, scholarly sources


What is authority? The author is knowledgeable about the topic. They have formal education or training. If the author is not known, the organization providing the information is reputable and unbiased.

How do you know? Examine or look up the author's credentials and affiliations. Can you find where they work? Where they graduated? Are those reputable, scholarly and unbiased organizations? Try to find more sources written by the author and examine them. Can you find articles or books they wrote on the same subject that were published in scholarly journals or presses?

If the author is not known, look at the “About Us” section of the website or look in the footer for the name of the sponsoring organization or group. Is the sponsoring organization staffed by people with formal education or training? Does the sponsoring organization have a specific agenda or purpose that may indicate bias?

Is the language and tone in the article measured and unbiased? Does it include multiple points of view and acknowledge weaknesses? Or is it biased? Does it only support one point of view? Is the tone inflammatory or insulting? Does it include many superlatives (ex. worst people…, best medicine…,) or sweeping generalizations (ex. everyone…, all the products…,).

Bottom line: Be skeptical of online articles that you cannot determine the credentials of the author or organization. Avoid “personal” websites or blogs. Avoid biased websites.


What is currency? The website has a recent publication/release date (for news articles) or “last updated” statement (for informational sites) and it has been updated recently.

How do you know? For legitimate news articles, the publication date will be included in the “by-line,” which is normally found either at the top or the bottom of the news story. Also look for “last updated” statements at the top, bottom, footer or header of a web page.

Bottom line: Be skeptical of online articles that do not indicate when they were published. Be aware that, without knowing the date of publication, it is possible our knowledge/understanding of the topic has significantly evolved since the information in the undated article was published.


What is accuracy? The claims made on the website are supported by verifiable facts.

How do you know? Does the article contain citations? Are there links to supporting facts, statistics, studies or quotes from witnesses/interviewed people? Can you find the facts, statistics, studies or quotes and verify they are correct and not taken out of context?

Bottom line: Be skeptical of articles with dead links or links to “evidence” that does not seems to match the claim it is supposed to support. Avoid articles that make claims without supporting evidence, such as studies, statistics or quotes that you can see in their full context.


Scholarly sources can generally be counted upon to be authoritative. But how can you determine if a source is truly scholarly?

Books: Scholarly books are printed by academic presses (ex. Cambridge University Press, Harvard University Press) or scholarly societies (ex. American Mathematical Society, American Psychological Association). Unless you are familiar with the university press or scholarly society, it is advisable to research them. Some presses, such as the Academic and Business Research Institute, sound scholarly, but they are unreliable.

Journals: Journals are also typically published by universities or scholarly societies/organizations. Reliable journals are peer-reviewed. You should be able to find information on their peer review process. They are indexed in the major bibliographic databases for their field (meaning you can find them in the library databases) and they have a verifiable impact factor. The impact factor is calculated using the number of times articles published in the journal over the previous two years were cited in the current year. The number of times an article is cited by other scholars is an indication of its value. Some journals are classified as predatory journals, meaning they offer to publish articles in exchange for money. These articles are typically not high quality scholarship.

A list of possibly unreliable or predatory publishers

The bottom line: Just because a book or article appears to be scholarly, unless you are thoroughly familiar with the university or organization that publishes it, you should do your research before trusting it.


For scholarly articles, you will always be able to determine the date of publication by referring to the copyright date of a book or the publication month and year of an article. But how should you use this information? You will often hear professors and librarians state that, for sciences, a source should be no more than five years old, since our knowledge in science is continuously evolving. For humanities, older works are acceptable. The reality, however, is more nuanced. Newer books and articles definitely contain the most recent scholarship on any subject. Older articles may be valuable to reveal how our understanding of a subject evolved to its present position. Therefore, some older works are referred to as “seminal works.” Seminal works, sometimes called pivotal or landmark studies, are books or articles that initially presented an idea of great importance or influence within a particular discipline. Reading a seminal work may be important to your research and limiting your search in a database to “the last 5 years” may exclude seminal works from your results. How can you identify a seminal work? If the database you are using lists the number of times the work is cited, that number will be relatively high. Most often, however, you learn which works are seminal to a subject as you read multiple articles and see certain articles repeatedly referenced.

The bottom line: Scholarship is a conversation that takes place in books and articles across time. The most recent knowledge is found in current books and articles, but sometimes critically important parts of the conversation can be found in older sources.


If a book was published by a reliable university press or an article was peer-reviewed, it must be fully accurate, right? Generally speaking, yes. Even so, reliable sources should still be read critically and examined for gaps or weaknesses in their methodology or findings/conclusions. Some questions you might ask when reading a scholarly book are article include:


  • Are the methods used consistent with other research cited in the article? Is enough information presented so that the research could be replicated/verified?
  • Is there any bias in the design? What issues or questions has the author not addressed? Is there a different perspective that should be considered? What other factors could have influenced the results?
  • How was the data collected? Was it obtained from a sample of a population? If so, was the sample representative? Are there any unrepresented populations?
  • Descriptive Statistics: Are the data reported clearly? Are the tables and figures clearly labeled and identified? Is it clear what, if any, manipulation was made to figures used in the article?
  • Inferential Statistics: Identify the inferential statistics used, if any. Were the appropriate tests conducted? If null hypotheses are tested, does the researcher indicate whether the hypotheses could be rejected and at what level of significance?


  • To what populations are the findings generalized? Are the conclusions supported by the study reported? What are the implications of the findings of the study?
  • Does the author(s) acknowledge limitations to their research? If so, what are they? Does the author(s) make suggestions for additional research?

The bottom line: Always be a critical reader, even when reading scholarly sources. Remember, you are part of the scholarly conversation. You can, and should, question and contribute your own ideas.


The anatomy of a scholarly article

Reading a scholarly article is very different from reading other types of information. Scholarly articles often contain very "academic" terminology and concepts. When you first begin reading scholarly articles, they may seem intimidating. Knowing more about how they are structured will make reading them easier. Most scholarly articles have a set structure:

Title: The title of an article should contain the keywords necessary to give the reader an idea what to expect the article will focus on.

Abstract (Summary): The abstract, generally written by the author(s) of the article, provides a concise summary of the whole article. Usually, it is under 250 words and highlights the focus, study results and conclusion(s) of the article. It is provided so that readers examining the article can decide quickly whether the article meets their needs.

Introduction (Why): In this section, the authors introduce their topic, explain the purpose of the study, and present why it is important, unique or how it adds to existing knowledge in their field. Look for the author's hypothesis or thesis here. 

Literature Review (Who else): Many scholarly articles include a summary of previous research or discussions published on this topic, called a "Literature Review".  This section outlines what others have found and what questions still remain.

Methodology / Materials and Methods (How): This section of a scholarly article explains the details of how the study was performed. There should be enough specifics so that you could repeat the study if you wanted. 

Results  (What happened): This section includes the findings from the study. Data gathered and statistical results are often found in the form of tables, charts, and graphs. Some papers include an analysis here.

Discussion / Analysis (What it means): This section should tell you what the authors felt was significant about their results. The authors analyze their data and describe what they believe it means.

Conclusion (What was learned): Here the authors offer their final thoughts and conclusions and may include: how the study addressed their hypothesis, how it contributes to the field, the strengths and weaknesses of the study, and recommendations for future research. Some papers combine the discussion and conclusion.

Reference list All scholarly articles end with a list of works cited throughout the article.

How to read a scholarly article

Read the abstract first It covers basics of the article. Questions to consider: 

  • What is this article about? What is the working hypothesis or thesis?
  • Is this related to my question or area of research?

Read the introduction and discussion/conclusion. These sections offer the main argument and hypothesis of the article. 

Questions to consider for the introduction: 

  • How is this research unique?
  • Will this tell me anything new related to my research question?

Questions for the discussion and conclusion: 

  • What does the study mean and why is it important?
  • What are the weaknesses in their argument?
  • Is the conclusion valid?

Read the literature review. In the literature review you will find the background and context for the current study. Questions to consider for the literature review:

  • What do we already know about this topic and what is left to discover?
  • What have other people done in regards to this topic?

Read the Methods/Methodology section. If what you've read addresses your research question, this should be your next section. Questions to consider:

  • How did the author do the research? Is it a qualitative or quantitative project?
  • What data are the study based on?
  • Could I repeat their work? Is all the information present in order to repeat it?
  • Is there a population they excluded in their study that I might include in mine?

Read the Results and Analysis. Now read the details of this research. What did the researchers learn? If graphs and statistics are confusing, focus on the explanations around them. Questions to consider: 

  • What did the author find and how did they find it?
  • Are the results presented in a factual and unbiased way?
  • Does their analysis agree with the data presented?
  • Is all the data present?
  • What conclusions do you formulate from this data? (And does it match with the Author's conclusions?)

If you got this far, read the entire article again in order. Reading the article twice will ensure that you have a full understanding of the article and the author's message. While re-reading, ask yourself:

  • Does what the author says agree with other information you have found on this topic?
  • How does this article fit into your research? What is important? What might you need to cite from it?

How to evaluate a scholarly article