  In the field of human intelligence, officers use an alphanumeric scale, known
as the Admiralty System, to rate the credibility of messages and the
reliability of their sources (NATO AJP-2.1, 2016). During this evaluation, they
are expected to estimate the credibility and reliability dimensions
independently of each other (NATO STANAG, 2003). However, empirical results
show that officers perceive these dimensions as strongly correlated (Baker et
al., 1968). More precisely, they consider credibility as playing the leading
role over reliability, the importance of which is only secondary (Samet, 1975).
In this paper, we present a formal evaluative procedure, called L(intel), in
line with these findings. We adapt dynamic belief revision to make credibility
the main dimension of evaluation and introduce dynamic operators to update
credibility ratings with the source's reliability. In addition to being
empirically sound, we show that L(intel) provides an effective procedure to
classify intelligence messages along the descriptive taxonomy presented in
Icard (2023).
