Fig. 1

One example (real medical case) of a Decision Process Matrix (DPM) showing a typical three-phase pattern in an 18 year old male patient with a four-day history of fever and abdominal pain. Numbers 01–46 represent the order in which options, cues and confidences occurred. 1. Option generation phase (from 01–11, highlighted in blue): three information (cues) 01 “adolescent patient”, 02 “abdominal pain”, and 03 “flu-like symptoms” consecutively led to two suspected diagnoses (options), namely 04 “Viral Gastroenteritis” and 08 “Lung infection”, each with the corresponding confidence of “quite probable” (05–07) for “Viral Gastroenteritis”, and “probable” (09–11) for “Lung infection”. This first phase follows the sequence cue(s) – mentioned option(s) – corresponding confidence(s) at the beginning of the diagnostic process. 2. Option verification phase (from 12–45, highlighted in yellow): With 15 further cues (including two physical examinations (40 and 42) and laboratory analysis (44)), the suspected diagnoses were verified in detail, resulting in an increase in the confidence in “Viral Gastroenteritis” and an exclusion of “Lung infection” in step 45. Due to information 12 “Cold extremities a couple of days ago”, an additional suspected diagnosis was mentioned (13 “Vascular problem”) with a confidence rating of “thinkable” (14) at the outset, which also ended up being excluded at step 37. This second phase follows the sequence (single) cue – confidence (according to that cue and one of the specific mentioned options before). Please note that there does not have to be a confidence value for each mentioned cue and option. 3. Determination of the final diagnosis (46, highlighted in red). After step 44, the laboratory analysis, the resident ruled out “Lung infection” and finally decided in step 46 on a final diagnosis of “Viral Gastroenteritis” and initiated the appropriate treatment. Following the membership functions of 13 verbal probability expressions [39], the following labels have been used for confidence ratings: “-4” = practically impossible, “-3” = improbable, “-2” = doubtful, “-1” = thinkable, “0” = possible, “+1” = probable, “+2” = quite probable, “+3” = very probable, and “+4” = practically certain