Borderline competence – from a complexity perspective: conceptualization and implementation for certifying examinations

Abstract

Passing or failing a candidate is a complex decision with one essential aspect being the definition of the required minimal level of competence. Commonly used methods, such as the Angoff method, are based on the 'borderline competence' concept; however, the method describes a 'borderline candidate'--a fictitious person, rather than describing a set of clearly defined criteria that describe a real person whose competencies fall between the clearly incompetent and clearly competent--the borderline zone. We argue that competence arises from the combination of discrete abilities across the entire subject domain including the interaction of some of those abilities, where strengths in some interacting abilities could partly compensate for weaknesses in others. We further argue that scores in the borderline zone may include combinations of abilities in which deficiencies are sufficiently compensated for by areas of strength, thus ensuring competency, while other, similarly scoring combinations do not include required compensations to ensure competency. We offer evidence that standard setting judges systematically and consistently assess the level of required ability on each individual task, taking into account the characteristics of those tasks based on the significance--being a function of the severity and incidence of that condition, and the ability to help--and the difficulty of executing that task. Consequently, a borderline zone of competence implies an overlap of competence and incompetence with respect to the level of performance on tasks of varying clinical significance. We further suggest that this overlap can be conceptualized as a folding of the 'competence plane' (consistent with a cusp catastrophe model) that cuts the space defined by performance levels on clinical conditions of varying significance, with their associated skills requirements. That folding defines the borderline zone in which competent candidates will perform most of the tasks in the borderline zone correctly whereas incompetent candidates will fail most tasks.