Primary Sources
n. ~ Material that contains firsthand accounts of events and that was created contemporaneous to those events or later recalled by an eyewitness.
Notes:
Primary sources emphasize the lack of intermediaries between the thing or events being studied and reports of those things or events based on the belief that firsthand accounts are more accurate. Examples of primary sources include letters and diaries; government, church, and business records; oral histories; photographs, motion pictures, and videos; maps and land records; and blueprints. Newspaper articles contemporaneous with the events described are traditionally considered primary sources, although the reporter may have compiled the story from witnesses, rather than being an eyewitness. Artifacts and specimens may also be primary evidence if they are the object of study.
Citations:
†(Personal communication, Leon C. Miller, 27 August 2004) Whether something is a primary or secondary source depends on how it is used, not some quality of the document or record itself. . . . For example, Sandburg's biography of Lincoln is a primary source for Sandburg researchers but a secondary source for Lincoln researchers.
†(Robyns 2001, p. 368) Primary sources, we must constantly reiterate, are the subjective interpretations of another person's observation of an event or activity. Not surprisingly, therefore, many professional historians have written that it is their duty to approach primary sources with a healthy skepticism in the research process.
Secondary Sources
n. ~ 1. A work that is not based on direct observation of or evidence directly associated with the subject, but instead relies on sources of information. - 2. A work commenting on another work (primary sources), such as reviews, criticism, and commentaries.
Definitions from Pearce-Moses, Richard A Glossary of Archival and Records Terminology 2005. http://www2.archivists.org/glossary/terms/p/primary-source
Informational Value - the information contained in the materials. Examples include the text of documents and visual elements of photographs.
Evidential Value - the information available about the creation of the materials. This may include indications of how an organization functioned, the working methods of the creator, or materials and technologies available and used in the creation of the materials.