Primary or Secondary?

During the course of your research, you might be asked to use primary and secondary sources. 'What is the difference?', you ask. Primary sources are those which were written during the period in which the information occurred. Secondary sources, however, are those reviews and accounts that were written after an event occurred.

Primary	Secondary
Primary sources are not necessarily the sources you primarly use, but they are the most fundamental information on the subject.	Secondary sources analyze and interpret primary sources and are used primarily for presenting the views of others about your primary sources.
Published at the time the event occurred, by someone involved in the actual event	Written about an event after it occurred
For historical events, a primary source on Abraham Lincoln would be either one written by Lincoln (such as The Gettysburg Address) or by someone who knew Lincoln. They could be documents or artifacts created during the time period.	For historical events, a secondary source on Abraham Lincoln could be a book, magazine article, or internet site written after his death.
Scientific research is often a primary source if it is written by the scientist who did the research and it includes information such as methods, materials, discussion, results, and conclusion. An example of this would be an article published in The Proceedings of the National Academy of Sciences.	Some examples of secondary sources may be a critical review of Shakespeare's Hamlet or an article written in Science News about a scientific discovery that was reported in another publication.