Scope: As you conduct research, you will consult different sources of information. A professor may request primary, secondary, or tertiary sources. The Mountain West Digital Library has a substantial number of both primary and secondary sources to help in conducting research. Depending on your subject and field of study, you may want to begin your research by looking at some secondary sources to get a good idea of what primary sources are available and what is being said about them. Then you can move on to looking at the primary sources to make your own interpretations.
Primary sources are original materials. They are from the time period involved and have not been filtered through interpretation or evaluation. Primary sources are original materials on which other research is based. They are usually the first formal appearance of results in physical, print or electronic format. They present original thinking, report a discovery, or share new information.
Note: The definition of a primary source may vary depending upon the discipline or context.
Secondary sources are less easily defined than primary sources. Generally, they are accounts written after the fact with the benefit of hindsight. They are interpretations and evaluations of primary sources. Secondary sources are not evidence, but rather commentary on and discussion of evidence. However, what some define as a secondary source, others define as a tertiary source. Context is everything.
Tertiary sources consist of information which is a distillation and collection of primary and secondary sources.