For example, a diary written by a survivor of the sinking of the Titanic would be considered a primary source of information on that historical event. A newspaper article written at the time of the sinking might also be considered primary if it was based on eye witness reports. A study of the effect of music on the achievement of first graders in a classroom documented by the observer would also be considered primary research. A secondary source either reports second hand events or research that has been previously documented or evaluates previously published works. Many college papers can be considered secondary sources because the researcher relies heavily on other people's research.
Some papers can include both secondary and primary research.
For example, if the previously mentioned study of the effects of music on first graders' achievement included as an introduction to the original study a review of previous studies done in that area, the review would be considered secondary research, while the report of the current study would be considered primary research.