Table 1 Critical decision method phases

Incident identification and selection

The first step of the CDM process. The participant selects an appropriate incident for probing. The participant is asked to give a detailed description of the incident from the beginning to end. For example, in this study, the ID experts identified a recent case that seemed complex to solve cognitively.

Timeline verification and decision point identification

The second step is to get a clear and refined overview of the incident structure, key events and segments. For each of the key events, the participants were asked for goals at that point. For example, in this study, the timeline verification started from the very moment the ID expert got involved with the case or was referred to the case.

Progressive deepening

The third step refers to points in the timeline where the interviewer probes the participants for additional details. As a result, more details about decision points, judgments and the decision-making process are revealed. This particular phase ensures that the participants are probed for specific and detailed information regarding cognitive skills, experiences and expertise. For example, in this study the experts were asked specific questions about their gut feelings and how they knew the information that suddenly occurred to them.

“What-If” queries

In this final phase, the participants are asked hypothetical questions regarding their incidents that further help to illuminate the implicit decision-making process of the experts. For example, the interviewer asked, “If the patient had contracted a different type of pathogen, how would you have responded?”