From Primary Sources at Yale:
"Primary sources provide first-hand testimony or direct evidence concerning a topic under investigation. They are created by witnesses or recorders who experienced the events or conditions being documented. Often these sources are created at the time when the events or conditions are occurring, but primary sources can also include autobiographies, memoirs, and oral histories recorded later. Primary sources are characterized by their content, regardless of whether they are available in original format, in microfilm/microfiche, in digital format, or in published format."
Locate obvious primary sources in the Colby Catalog by using an artist/author name and a term such as: sources, letters, autobiographies, diaries, or another term from the list below. The library also subscribes to many online primary resource collections: textual, media, visual, and music. Colby's Special Collections provides a wealth of materials relating specifically to the College and other literary and historical collecitons.