There is a major distinction that runs through the sources recorders use. Sources of information are sometimes people, or organisations containing people.
Where people are being considered, sources can range from a government or armed group, through an NGO or media organisation, to a family, or a single individual who has witnessed or documented something. The distinction is that these people give recorders information directly, either verbally or in documents. When dealing with people as sources, casualty recorders are taking into account such factors as how to access and gain the trust of the people concerned, and how to assess their capacities, authority, motivation and credibility.
THE RANGE OF SOURCES IN CASUALTY RECORDING, p. 4