Primary, Secondary, and Tertiary Sources of Information in the Sciences

What are the different types of sources of information used in research? 

Generally, there are three basic types of information sources in research including primary, secondary, and tertiary.  They are as follows:

Primary Sources:  Primary sources of information are first hand accounts of research or an event including original scholarly research results, raw data, testimony, speeches, historic objects or other evidence that provides unique and original information about a person or an event. These sources were created at the time which the observation or event occurred but can also be created later by an eyewitness.  Primary sources allow researchers direct access to original ideas, events, and data. Some examples of primary sources include published original scholarly research articles, original creative works, and eyewitness accounts of contemporaneous events.

Secondary Sources:   Secondary sources analyze, synthesize, evaluate, and interpret primary sources (or other secondary sources). Secondary sources are created after an event has occurred and are written by someone who did not experience or observe the event first hand.  Some examples of secondary sources include articles that interpret original scholarly research results and critiques of original creative works.  Secondary sources are not evidence, but rather comment on and discuss previous evidence.

Tertiary Sources:  Tertiary sources of information provide broad overviews or condensed narratives of topics. They analyze and summarize the information in primary and secondary sources in order to provide background on a idea, event, or topic. Tertiary resources often provide data in a convenient form and provide context of the topic for a frame of reference.  Some examples of tertiary sources include textbooks, dictionaries, encyclopedias, and almanacs.

Common elements of a scholarly article:

• Authors and their credentials
• Abstract
• Introduction including background information on subject, literature review, statement of research problem, and hypothesis
• Methods
• Results
• Discussion
• Limitations of research
• Recommendations for further research
• Conclusion
• References

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