Sources of information for periods can be classified into primary and secondary sources. Primary sources are first-hand information sources that are as close as possible to the origin of the information or idea under study. They are created during the time the events occurred, such as newspaper articles from the period, correspondence, diplomatic records, original research reports and notes, diaries, autobiographies, oral histories, government documents, photographs, news film footage, film, archival materials, and relics and artifacts. Primary sources can also include items created after the events occurred, but that recount them such as autobiographies and oral histories.
Secondary sources, on the other hand, are accounts or interpretations of events created by someone without firsthand experience. They put primary sources in context, comment, summarize, interpret or analyze information found in primary sources. Examples of secondary sources include textbooks, literature reviews, and journal articles that are not primary reports of new research.
When looking for primary sources, it is important to ask questions such as when and where it was created, who created it, and for what purpose or audience it was produced. Depending on the topic and time period being studied, different kinds of primary sources may be available, such as court cases, legislative documents, statistics, government reports, and personal correspondence.
