Human intelligence (frequently abbreviated HUMINT) is intelligence gathered by means of interpersonal contact, as opposed to the more technical intelligence gathering disciplines such as signals intelligence (SIGINT), imagery intelligence (IMINT) and measurement and signature intelligence (MASINT).
NATO defines HUMINT as "a category of intelligence derived from information collected and provided by human sources." Typical HUMINT activities consist of interrogations and conversations with persons having access to information.
The manner in which HUMINT operations are conducted is dictated by both official protocol and the nature of the source of the information. Within the context of the U.S. military, most HUMINT activity does not involve clandestine activities. Both counter intelligence and HUMINT do include clandestine HUMINT and clandestine HUMINT operational techniques.
HUMINT can provide several kinds of information. It can provide observations during travel or other events from travelers, refugees, escaped friendly POWs, etc. It can provide data on things about which the subject has specific knowledge, which can be another human subject, or, in the case of defectors and spies, sensitive information to which they had access. Finally, it can provide information on interpersonal relationships and networks of interest.
HUMINT is both a source of positive intelligence, but also of information of strong counterintelligence value. Interviews should balance any known information requirements of both intelligence collection guidance and of counterintelligence requirements.
Sources may be neutral, friendly, or hostile, and may or may not be witting of their involvement in the collection of information. "Witting" is a term of intelligence art that indicates that one is not only aware of a fact or piece of information, but also aware of its connection to intelligence activities. Examples of HUMINT sources include, but are not limited to, the following: