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. While these are sometimes accounts by participants, in most cases they are written by journalists or other observers. The important thing is to distinguish between material written at the time of an event as a kind of report, and material written much later, as historical analysis. Photographs, audio recordings, moving pictures or video recordings documenting actual events.
Research reports in the sciences and social sciences.
Especially for recent social history, the best evidence of broad developments in society is often in the form of social science surveys or research studies. This research may be reported in book form, government reports or most commonly in articles published in scholarly journals. Since these are generally very limited in availability and in what they reveal, however, it is also possible to make use of ideas and images conveyed in the mass media, and even in literature, film, popular fiction, self-help literature, textbooks, etc. Again, the point is to use these sources, written or produced at the time, as evidence of how people were thinking. Secondary sources are works that interpret or analyze an historical event or phenomenon.