Scope: As you conduct research, you will consult different sources of information. A professor may request primary, secondary, or tertiary sources. What does that mean? This guide explains these terms and gives examples for each category.
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.
For more detailed information on how to find primary sources in our library see the Primary Sources Research Guide.
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.
Comparison across the disciplines
|Art||Painting by Manet||Article critiquing art piece||Art museum guide|
|Chemistry/Life Sciences||Einstein's diary||Monograph on Einstein's life||Dictionary on Theory of Relativity|
|Engineering/Physical Sciences||Patent||NTIS database||Manual on using invention|
|Humanities||Letters by Martin Luther King||Web site on King's writings||Encyclopedia on Civil Rights Movement|
|Social Sciences||Notes taken by clinical psychologist||Magazine article about the psychological condition||Textbook on clinical psychology|
|Performing Arts||Movie filmed in 1942||Biography of the director||Guide to the movie
Librarians at the University of Maryland were the authors and inspiration for the material. Original webpage: