6.2 Kinds of Sources

Types of Knowledge

Sources are useful for gathering knowledge, which DataCenter categorizes into three types:

• Cultural and spiritual knowledge are the cultural practices and wisdom passed down in our communities. This knowledge is often shared through culture and traditions. Each of the following can provide cultural and spiritual knowledge:
  • Elders
  • Neighbors
  • Friends and family
  • Stories
  • Songs and dances
  • Ceremonies
  • Festivals
• Experiential knowledge is knowledge gained through lived, day-to-day experience. Experiential knowledge can come from:
  • Personal experiences
  • First-hand observations within your community (e.g., environmental racism, police brutality, or poverty)
  • Hands-on practice
• Mainstream and institutional knowledge are the facts and data published by research professionals (often from outside the communities they study). These forms of knowledge often appear in:
  • Newspapers
  • University publications
  • Police reports

All three sets of knowledge are interconnected and form the entirety of information about an issue. However, each can also be skewed to represent a publisher’s specific viewpoint or agenda. You should be mindful of your audience and goals when deciding which forms of knowledge you want to incorporate into your work. Note that all three are necessary to accurately represent issues related to a given community.

Primary, Secondary, and Tertiary Sources

When we gather cultural, spiritual, experiential, mainstream, and institutional knowledge into a set of sources, we can determine how to use these sources by establishing whether they are primary, secondary, or tertiary. These designations help us to understand the level of interpretation that has gone into a source, and thus how we might orient ourselves to, or put ourselves in conversation with, that source. Not all research will use each type of source, but understanding these general categories can help you to identify other possible sources to locate for your research.

Primary Sources

Primary sources can include raw data currently under analysis, first-hand accounts, and historical documents. Examples include:

• Original manuscripts
• Archival documents
• Cultural practices and traditions (e.g., recipes, dances, and stories)
• Survey results
• Lab results
• Anecdotes and stories
• Texts of laws
• Speeches
• Artifacts
• Letters
• Photographs
• First-hand accounts and experiences
• Works of literature and art

For example, if your topic is pine beetle infestations, your data will likely come from what researchers have found in specific geographical areas. You can collect your own data and information to use as primary sources, too.

Secondary Sources

Secondary sources interpret primary source materials and are subject to the perspectives of their authors. Examples include:

• Scholarly journal articles and books
• Review articles and meta-analyses
• Newspaper and magazine editorials, op-eds, and investigative pieces
• Political commentaries
• Documentaries
• Interviews with experts
• Podcasts

These can be used to assist in answering research questions and providing commentary about fields or topics of interest.

Tertiary Sources

These are general forms of information that synthesize primary and secondary sources without providing analysis or interpretation. Examples include:

• Wikipedia
• Encyclopedias
• Textbooks

Use these sources as a way to investigate your interests in a topic area; they can help you find out exactly what it is you want to discuss in your research. However, these sources are not the best or most reliable options for supporting a research argument, as the information in these sources tends to be generalized and simplified or, in the case of Wikipedia, inconsistently fact-checked.

Practice Exercise

Categories of Mainstream and Institutional Sources

Assignments in your college courses will often require you to draw on sources for mainstream and institutional knowledge. Although most research writing in college requires you to engage with what we refer to as “scholarly” sources, there may be a reason to use other kinds of sources, including “popular” and “gray literature” sources, which we discuss below. Different sources contain different types of information, and are found using different tools. Sources can be sorted into a few key categories, and each category has its particular uses. Below, we name and define each category:

Now, let’s review the definitions of each category.

Scholarly Sources

Scholarly sources are written by researchers for researchers. Scholarly sources rely on a process called “peer review,” in which other researchers in the same field evaluate the appropriateness of their methods and the accuracy of their findings. Scholarly articles generally do not get published unless they make a contribution to research in their given field.

You can often identify scholarly articles because they appear in publications with titles that include words like “journal” and “research.” Articles from these publications do not typically include images designed to draw interest; instead, they often include data-driven graphics, like charts and tables. They also tend to include lots of citations, because academic researchers are dedicated to advancing knowledge within their field and demonstrating how their own work is in conversation with others who have published on their same topic.

While some of these articles are freely available on the internet, many of them can only be found through library databases or journal websites. In many cases, these articles are hosted on websites that require a subscription. Fortunately, college and university libraries are frequently subscribers, and you can access many of these sites via the Santa Clara University library databases [Website]. When these articles aren’t available through our databases, you can still access them through a process called “interlibrary loan” [Website]. Refer to the “Collecting Academic Sources” [Chapter 6] section to learn more about how to find them.

Bias in Scholarly Sources

Although you will almost certainly be expected to use scholarly sources for most of your college research projects, scholarly publications can still be biased. Be sure to consider the following biases when evaluating any source—even a scholarly one:

• Funding bias can occur when research is funded by a specific organization. That doesn’t mean the research is of poor quality, but there may be some bias if the study favors its financial supporters. One example might be a study of a medication funded by a pharmaceutical company. Bias could include overemphasizing desired results or suppressing undesired data.
• Selection bias occurs when study participants do not represent the general population due to the selective inclusion or exclusion of study participants. For example, if a study focuses on the impacts of a healthy diet on children with type 2 diabetes, but only includes girls between the ages of nine and 12 living in California, the results may not be applicable to the general population.
• Media bias generally indicates selectivity in what stories and perspectives are covered, such as when only specific stories or interpretations are covered. An example might be an article that includes primarily conservative or liberal news outlets or sensational stories. Citing The Epoch Times, a far-right publication, will probably present a different perspective than citing The New York Times, a center-left publication. In science reporting, bias emphasizes views not supported by evidence.
• Finally, there could be bias in the literature review. A study will typically have a literature review, presenting a comprehensive overview of current knowledge on a topic. If the author excludes information, whether intentionally or unintentionally, this could create a distorted view of an issue.

Bias also affects what research is published in scholarly journals. A 2023 study from Knowledge Works Global, Ltd. [Website] outlined these areas of bias within academic publishing that may prevent you from accessing diverse perspectives in your scholarly sources. Here’s an overview of their findings:

“When it comes to academic and research publishing, there are many examples of how these biases impact the publishing process and challenge a publisher’s overall DEI mission, including:

• Editorial board and reviewer selection bias: As we noted in our report, the publishing industry has traditionally been made up of members from privileged communities. Disparities in editorial board and reviewer composition by race, gender, ethnicity, institution, and geography can impact the type of research published.
• Review outcome bias: Similarly, peer review struggles with disparities in race, gender, ethnicity, institution, and geography, which can impact review outcome.
• Citation bias: It is human nature to refer to studies we know, but when researchers repeatedly reference specific materials or studies because of their personal preference or experience rather than a diversity of materials, this can show bias.
• Dissemination bias: At times, the outcome of a study is not what researchers expect, so they may not disseminate new findings that might be useful to other studies or groups.
• Gray-literature bias: This is when unpublished research findings or research results that have received little or no exposure in an academic field of study are excluded, despite their potential benefit to the larger field of research.
• Language bias: This type of bias occurs when researchers publish reports written in a particular language, irrespective of the nature and direction of the results.
• Outcome reporting bias: Researchers choose to publish specific outcomes based on the results.
• Time-lag bias: There’s an obvious disparity between the timeframe for publishing negative and positive research results.

While identifying implicit biases isn’t enough to eliminate them, highlighting some of the larger challenges we face both consciously and subconsciously is the first step in creating change. In order to advance scholarly communications that reflect the full range of perspectives and reach the widest audience, it is important to recognize different areas of bias and how they impact our work.” (Knowledge Works Global, Ltd.)

So, as you engage with scholarly sources, remember that they are not infallible. Be aware of their potential biases as you read and evaluate [Chapter 6] them, address any research gaps, and draw from other types of sources and knowledge to ensure your own research presents a more equitable view (see “Research Justice” [Chapter 5]).

Popular Sources

Popular sources are written for interested audiences that may or may not have any specialized knowledge. While many of these sources are reputable, they are not considered scholarly because they aren’t necessarily written by subject-matter experts, are not subject to peer review, and often lack references. People usually find them through Google or other similar search engines, and they may be available for free. However, many newspapers and magazines put their content behind paywalls. We don’t begrudge them that—it costs money to pay reporters, editors, and fact-checkers. If you don’t pay for a subscription to a particular publication, don’t despair! You might be able to access it through your university or public library. At SCU, search for the title of any publication in our SCU library [Website] to see if we have access (see the “Navigating Your Library” section for more on library searching).

As with scholarly sources, it is important to evaluate popular sources [Chapter 6] that you find and be aware of their biases. Moreover, be aware that popular search engines used to seek out non-scholarly sources may have biased algorithms. For more on search engine bias, see the section “How to Google Effectively” in “Collecting Academic Sources” [Chapter 6].

Gray Literature

Gray literature refers to sources written by experts on a subject who may not be affiliated with an academic or government institution. They are often published through non-scholarly avenues, such as preprint sites. The following video from the University of Guelph explains gray literature:

Gray literature may require you to go directly to the government or professional organization that published it. It may also be posted on open-access preprint sites like arXiv [Website] or open data repositories like data.gov [Website]. Since gray literature is often created by subject matter experts trained in academic institutions or funded by interested parties, it’s important to acknowledge that it may contain biases as well. Remember to evaluate gray literature with the same scrutiny you would apply to any other source and address any research gaps. Want to get started? Princeton University has developed this “Technical Reports & Grey Literature” [Website] libguide listing several gray literature resources.