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Understanding Scientific Literature: Primary, Secondary, and Tertiary Sources

Primary Sources

What they are: 

In the sciences primary sources are original research or data. Primary sources can include any of the following publications 

  • Journal Articles -- Journal articles can be primary sources if they contain original research, but keep in mind that not all journal articles are primary sources.
  • Reports -- Reports are publications on research that are published independently of a journal. They are often published by governments or companies.
  • Theses and Dissertations -- Theses and Dissertations are the original research of an academic working on a degree. 
  • Conference Proceedings -- Conference Proceedings are a collection of papers that have been presented at a conference. 
  • Published Data -- Data can be considered a primary source, as it is the product of original research.

Why use them:

 Primary sources are a researchers firsthand account of their research. They provide an in depth view into how the research was conducted, and may contain supplemental materials like questionnaires used. A summary of a study or experiment in a book or review paper may not discuss all the findings, and you can gain more insight into a particular topic or issue by looking at the primary sources. 

How to find them: 

Resources for finding primary sources include: 

  • Databases and Indexes -- The exact database or index you choose to search will depend on the discipline you are searching in. 
  • Review Papers -- Review papers are often synthesized from other researchers to give an in-depth understanding of the current state of knowledge on a topic. If you have found a review paper when you are looking for a research paper don't fear! If the review paper is on the write topic it will cite plenty of research papers on your topic of interest. 

Secondary Sources

What they are:

In the sciences secondary sources analyze, interpret, summarize, or evaluate the findings of primary sources. Secondary sources can include any of the following publications: 

  • Journal review articles -- A review article summarizes past research on a given topic. Review articles can range from highly intensive systematic or integrative reviews or less rigorous literature reviews.
  • Textbooks -- The information in textbooks in the sciences is the product of past research.  
  • Monographs -- A monograph is a book-length scholarly publication dedicated to a single topic. 

Why use them:

Secondary sources can save you time by providing information on the current state of knowledge on a given topic, and also as a way to find primary resources. If you are interested to know what are important, seminal papers in on a topic look at what papers are cited in a textbook on that topic. Review papers can give you in-depth information on a particular research area. Secondary resources are also often less technical than primary resources. 

How to find them: 

Resources for finding secondary sources 

  • Databases and Indexes -- Databases and indexes are particularly useful for finding review articles.  
  • The Library Catalog -- The library catalog will help you locate books on the topic you are interested in. 

Tertiary Sources

What they are: 

In the sciences tertiary resources are synthesized from primary and secondary resources. They usually provide summaries on the current state of knowledge. Tertiary sources can include the following publications: 

  • Encyclopedias
  • Dictionaries 
  • Factbooks 
  • Almanacs 

Why use them:

Tertiary sources can be viewed as a jumping off point for your own research. They provide succinct summaries on topics, and can be a good way to familiarize yourself with the terminology on a topic before you begin searching the databases. 

How to find them: 

Resources for finding tertiary sources include: 

  • The Library Catalog -- Keep in mind a majority of our encyclopedias are in the reference room. 
  • LibGuides and the Library Website -- We have a number of digital encyclopedias. Check the LibGuide for your field to see what digital encyclopedias we might offer!