Table 1.

Error classification definitions and examples adapted from Rasmussen’s Cognitive Error Taxonomy.¹⁶

Error Level		Definition	Example
Cognitive
	Information	Inability to detect cues arising from the change in system state.	Resident continues to use tacker multiple times despite the fact that it is out of tacks. Does not realize that no tacks are going into mesh.
	Diagnostic	Inaccurate diagnosis of the system state on the basis of the information available.	Resident recognizes mesh is slipping and incorrectly associates the issue with the size of the mesh when it is actually due to the suture slipping through the abdomen. Later correctly realizes the extent of the problem and how far it had slipped.
	Strategy	Selection of a strategy that fails to achieve the intended goal.	Resident does not put anchoring sutures in mesh.
Technical
	Mechanical	Occurrence of structural or mechanical failures that do not provide an opportunity for resident intervention.	Suture slips through Endo Close™ device.
	Procedure	Execution of a procedure inconsistent with the strategy selected.	Resident puts an inappropriate number of anchoring sutures into mesh.
	Action	Failure to properly execute the procedure.	Resident makes multiple attempts at snaring the suture with the Endo Close™ device.