A primary source is firsthand testimony or direct evidence concerning a topic being researched. The nature and value of a source cannot be determined without reference to the topic and questions it is meant to answer. The same document, or other piece of evidence, may be a primary source in one investigation and secondary in another. The search for primary sources does not, therefore, automatically include or exclude any category of records or documents. Primary sources enable the researcher to get as close as possible to the truth of what actually happened during an historical event or time period.
Primary sources are the evidence left behind by participants or observers.
Memoirs and autobiographies. These can be less reliable since they are usually written long after events occurred and may be distorted by bias, dimming memory or the revised perspective that may come with hindsight. On the other hand, they are sometimes the only source for certain information. Records of organizations and agencies of government. The minutes, reports, correspondence, etc. of an organization or agency serve as an ongoing record of the activity and thinking of that organization or agency.