Definitions of what is primary or secondary differs across the disciplines. For the sciences, this is how we would define the different types of sources:
Primary source literature in the sciences:
Secondary source literature in the sciences:
Tertiary sources in the sciences:
Characteristics of primary sources in the sciences include:
|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)|
|Theses & dissertations|
To find primary source literature in the sciences, use library databases. Research guides can help you identify databases for the discipline you are interested in.
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.