Types of Sources
Information is found everywhere, but not all information sources are the same. To start thinking about the types of sources we use when we look for information, let's consider the process it took to create that information:
Use the tabs below to explore primary, secondary, and tertiary sources.
Primary Sources
Primary sources are products of original research. Primary sources are the first appearance of research findings (publications and presentations) and often provide a description of how the original research was conducted. In the sciences, these often include data sets and results found from empirical observations and experiments. Primary sources form the basis for further research and interpretations on a subject as new ideas may not be fully refined or validated within the original study (ex. a secondary source uses a primary source to validate and interpret results).
Examples include:
Secondary Sources
Secondary sources are accounts written after an event or original research has taken place to interpret, discuss, and evaluate a primary source. They tend to summarize existing knowledge so can be used to compare different ideas and theories over time. Since a secondary sources include commentary, the context of the writing is important to consider when evaluating the value of the source to your research.
Examples include:
Tertiary Sources
Tertiary sources are a generalized resource that use distilled and condensed information. While they rarely contain original material, they tend to include a collection of references tracing back to primary and secondary sources. Tertiary sources can be a good starting place for your research to look up data or get an overview of your topic.
Examples include:
| Subject | Primary Source | Secondary Source | Tertiary Source |
| Biology | Case study of Zika patient | Review article about Zika | Encyclopedia entry on Zika |
| Chemistry | Chemical patent | Book about chemical reactions | Table of related reactions |
| Agriculture | Results from a scientific GMO study | Journal article about GMOs | Encyclopedia entry on GMOs |
Source: Virginia Tech University Libraries. Primary, secondary, and tertiary sources.
Popular and Scholarly Sources
In addition to identifying sources as primary, secondary, or tertiary, sources can also be classified as popular or scholarly. Scholarly sources tend to be peer-reviewed (a rigorous editing process in which experts verify the information). To start thinking about the types of sources we use when we look for information, let's think about the author, the intended audience, and the publishing process.
Use the tabs below to explore the differences between popular and scholarly sources.
Popular vs. Scholarly Sources
Popular Sources
Imagine the types of magazines and newspapers that you would find at a bookstore or in the grocery store. We refer to these types of periodicals as "popular sources"; they are geared to reach a more general audience and written in non-technical language.
Examples
Examples include magazines, newspapers, websites, blogs, etc. Search and browse the following popular science resources to locate an article.
Scholarly Sources
In contrast to popular sources, scholarly sources are written primarily by scientists, for scientists. The goal of a scholarly source is to communicate new scientific research in the context of past research. The language in scholarly sources is often technical and publishing often follows a rigorous editing and approval process making the final product peer-reviewed.
Examples
Examples could include articles, reviews, conference papers, grey literature, books, etc. Scholarly journal titles include: Nature, Proceedings of the National Academy of Science, ACS journals. Visit some of the geography databases below to search and browse for scholarly articles.
Verify Peer-Reviewed Sources
Look up a journal title (not an individual article title) in Ulrichsweb with the link below to verify whether the journal is peer-reviewed.
Look for this referee jersey icon in the Ulrich search results to confirm that a journal is refereed/peer-reviewed. Refereed journals use a review process in which articles are reviewed by experts and respected researches to verify the validity and value of the article to the field.
