Identifying Primary and Secondary Sources
Definitions of what is primary or secondary differ across the disciplines. For the sciences, this is how we would define the different types of sources:
Primary source literature in the sciences:
- documents the results of original research
- is written by those who have conducted the research
- includes firsthand information about their methodologies, data, results, or conclusions.
Secondary source literature in the sciences:
- summarizes, compares, critiques, or interprets the primary literature.
Sometimes, you may run across tertiary sources in the sciences. These are collections of primary and/or secondary sources.
Characteristics of primary sources in the sciences include:
- Report original research, ideas, or scientific discoveries for the first time
- Report results/findings/data from experiments or research studies
- May also be referred to as primary research, primary articles, or research studies
- DO NOT include meta-analyses, systematic reviews, or literature reviews - these are secondary sources
- Are frequently found in peer-reviewed or scholarly journals
- Should explain the research methodology used (randomized controlled trial, etc)
- Frequently include methods, results, and discussion sections
- Are factual, not interpretive
Examples of Sources
| Primary Sources | Secondary Sources |
| Research articles published in scholarly, peer-reviewed journals | Summaries, critiques, or interpretations of primary literature |
| Clinical trials | Review articles |
| Interviews | Textbooks (can also be a tertiary source) |
| Correspondence | Dictionaries (can also be a tertiary source) |
| Patents | Directories (can also be a tertiary source) |
| Lab notebooks | Encyclopedias (can also be a tertiary source) |
| Data sets | |
| Theses & dissertations | |
| Technical Reports |
Where to find primary sources
To find primary source literature in chemistry, click the Find Articles link to the left.
Note: The library databases may contain references to both primary and secondary literature. You will need to examine each resource carefully to determine which one it is.