Informational sources can be classified roughly into three groups - primary, secondary, and tertiary - that reflect their originality. These groups are defined generally below.
Primary
Primary sources are original, uninterpreted information.
Unedited, firsthand access to words, images, or objects created by persons directly involved in an activity or event or speaking directly for a group. This is information before it has been analyzed, interpreted, commented upon, spun, or repackaged. Depending upon the context, these may include research reports, sales receipts, speeches, e-mails, original artwork, manuscripts, photos, diaries, personal letters, spoken stories/tales/interviews, diplomatic records, etc.
Think of physical evidence or eyewitness testimony in a court trial. Instructions for Paste and Spellcheck
Secondary
Secondary sources interpret, analyze, or summarize.
Commentary upon, or analysis of, events, ideas, or primary sources. Because they are often written significantly after events by parties not directly involved but who have special expertise, they may provide historical context or critical perspectives. Examples are scholarly books, journals, magazines, criticism, interpretations, and so forth.
Think of a lawyer's final summation or jury discussion in a court trial.
Tertiary
Tertiary sources compile, index, or organize sources.
Sources that analyzed, compiled, and digested secondary sources included mostly in abstracts, bibliographies, handbooks, encyclopedias, indexes, chronologies, etc.
Think of an index that lists all the cases heard by this court during the year.
Thank you, UConn Library!
In the humanities and social sciences, primary sources are the direct evidence or first-hand accounts of events without secondary analysis or interpretation. A primary source is a work that was created or written contemporary with the period or subject being studied. Secondary sources analyze or interpret historical events or creative works.
Primary sources
A primary source is an original document containing firsthand information about a topic. Different fields of study may use different types of primary sources.
Secondary sources
A secondary source contains commentary on or discussion about a primary source. The most important feature of secondary sources is that they offer an interpretation of information gathered from primary sources.
Tertiary sources
A tertiary source presents summaries or condensed versions of materials, usually with references back to the primary and/or secondary sources. They can be a good place to look up facts or get a general overview of a subject, but they rarely contain original material.
Examples
| Subject | Primary | Secondary | Tertiary |
|---|---|---|---|
| Art | Painting | Critical review of the painting | Encyclopedia article on the artist |
| History | Civil War diary | Book on a Civil War Battle | List of battle sites |
| Literature | Novel or poem | Essay about themes in the work | Biography of the author |
| Political science | Geneva Convention | Article about prisoners of war | Chronology of treaties |
http://www.lib.vt.edu/help/research/primary-secondary-tertiary.html
In the sciences, primary sources are documents written by the person(s) who conducted the original research. For example, a primary source would be a research article where scientists describe their methodology, results, and conclusions about the genetics of tobacco plants. A secondary source would be an article commenting or analyzing the scientists' research on tobacco.
Primary sources
These sources are where the results of original research are usually first published in the sciences. This makes them the best source of information on cutting edge topics. However the new ideas presented may not be fully refined or validated yet.
Secondary sources
These sources tend to summarize the existing state of knowledge in a field at the time of publication. Secondary sources are useful places to learn about your topic in depth. They are useful places to find comparisons of different ideas and theories and to see how they may have changed over time.
Tertiary sources
These types of sources present condensed material, generally with references back to the primary and/or secondary literature. They can be a good place to look up data or to get an overview of a subject, but they rarely contain original material.
Examples
| Subjects | Primary | Secondary | Tertiary |
|---|---|---|---|
| Agriculture | Primary Research article paper on dairy microbiology | Review article on the current state of dairy microbiology | Encyclopedia article on dairy microbiology |
| Chemistry | Chemical patent | Book about organic chemical reactions | Handbook of related organic reactions |
| Physics | Conference proceeding on high energy physics | A book about the current state of the field of high energy physics | Dictionary of high energy physics |
modified fromhttp://www.lib.vt.edu/help/research/primary-secondary-tertiary.html
What type of information do you need?
What type of source(s) match(es) that need?
What format of source(s) match(es) that need?
What can you tell about how a source was made?
Does this help you decide if it is useful to you?
Does your project's format match that need?
What assumptions/judgments do you make about the source based on the format?
What does your project's format tell you about the information you are creating?
Fiction
Non-fiction
“1. Categorizing Sources.” 2015. Choosing & Using Sources: A Guide to Academic Research, Teaching & Learning, Ohio State University Libraries, licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted. https://ohiostate.pressbooks.pub/choosingsources/chapter/categorizing-sources/.
Generally, when referring to databases, especially academic (college and university) library databases, we are referring to Scholarly resources. Specifically Scholarly & Peer-Reviewed articles.
Each database contains a collection of information about articles (in this case). The database could contain a broad selection of subjects or disciplines, such as Academic Search Complete. Others contain specific information, such as Agricola.
Check out our A to Z list of Databases to see the many different types. You will see video databases, reference resources, as well as other types of information.
Two of my favorite databases are:
Information Timeline Graphic by adstarkel. Used under CC BY-NC-SA 2.0
