Intelligence source and information reliability

Intelligence source and information reliability rating systems are used in intelligence analysis. This rating is used for information collected by a human intelligence collector.[1][2] This type of information collection and job duty exists within many government agencies around the world.[3][4]

According to Ewen Montagu, John Godfrey devised this system when he was director of the Naval Intelligence Division (N.I.D.) around the time of World War II.[5]

The system employed by the United States Armed Forces rates the reliability of the source as well as the information. The source reliability is rated between A (history of complete reliability) to E (history of invalid information), with F for source without sufficient history to establish reliability level. The information content is rated between 1 (confirmed) to 5 (improbable), with 6 for information whose reliability can not be evaluated.[6]

For example, a confirmed information from a reliable source has rating A1, an unknown-validity information from a new source without reputation is rated F6, an inconsistent illogical information from a known liar is E5, a confirmed information from a moderately doubtful source is C1.

The evaluation matrix as described in the Field Manual FM 2-22.3 (see also Admiralty code):[6]

Source reliabilityEdit

Rating Description
A Reliable No doubt about the source's authenticity, trustworthiness, or competency. History of complete reliability.
B Usually reliable Minor doubts. History of mostly valid information.
C Fairly reliable Doubts. Provided valid information in the past.
D Not usually reliable Significant doubts. Provided valid information in the past.
E Unreliable Lacks authenticity, trustworthiness, and competency. History of invalid information.
F Reliability unknown Insufficient information to evaluate reliability. May or may not be reliable.

Information credibilityEdit

Rating Description
1 Confirmed by independent Sources Logical, consistent with other relevant information, confirmed by independent sources.
2 Probably true Logical, consistent with other relevant information, not confirmed.
3 Possibly true Reasonably logical, agrees with some relevant information, not confirmed.
4 Doubtful Not logical but possible, no other information on the subject, not confirmed.
5 Improbable Not logical, contradicted by other relevant information.
6 Difficult to say The validity of the information can not be determined.


  1. ^ "What Does an Army Human Intelligence Collector Do?". The Balance. Retrieved 2017-09-10.
  2. ^ "Human Intelligence Collector |". Retrieved 2017-09-10.
  3. ^ "Covert Human Intelligence Sources | MI5 - The Security Service". Retrieved 2017-09-10.
  4. ^ "New chief of Mossad, Israel's intelligence agency, has 30 years of experience in operational, intelligence and executive positions". EIPA. 2015-12-16. Retrieved 2017-09-10.
  5. ^ Montagu, Ewen (1977). Beyond Top Secret U. Peter Davies Ltd. p. 21.
  6. ^ a b Human Intelligence Collector Operations. LLMC. Field Manual FM 2-22.3 – via Google Books.