Good clinical judgment is an essential component of safe surgical practice, but it remains difficult to define, let alone objectively assess. In an effort to better understand surgical judgment, a series of studies characterized a phenomenon called ‘slowing down.’ This phenomenon describes the transition from a routine mode of operating to a more effortful one in the critical moments of operative practice, and is suggested to be a hallmark of expert judgment. Slowing down moments can be either planned (identified before the procedure) or unplanned (in response to emergent intraoperative information). In recent work, these slowing down moments were studied with expert surgeons under standardized conditions. To explore the planned moments, experts were asked to think aloud while reviewing preoperative CT scans for pancreas cancers, approaching each scan as if preparing to operate on the patient. To explore the unplanned moments, experts were asked to think aloud while watching edited videos of laparoscopic gallbladder surgeries, imagining themselves in the operating room observing each procedure. Findings suggest that experts are consistent with one another in the recognition of cues that inform clinical decision-making, but inconsistent with respect to the clinical implications of these cues. While these findings provide valuable insight into the nature of expert preoperative and intraoperative surgical judgment, further exploration is required. The current proposal seeks to extend this recent work to surgical trainees at different training levels (junior residents, senior residents, and fellows), who will be asked to think aloud while reviewing the same CT scans and watching the same gallbladder videos used with the expert groups. Qualitative and quantitative comparisons between trainees and experts will lead to a better understanding of the development of surgical judgment, and differences will inform the development of a robust assessment tool for this crucial aspect of competent clinical performance.