ABSTRACT
Simon’s scissors metaphor provides a great image to help us wrap up the theoretical context for our approach to interface design. Situation awareness is sometimes treated as if it were a single entity that resides completely within the head of a domain practitioner. As the previous two chapters suggest, situation awareness is more properly considered as a joint function of both the constraints of the work domain (Chapter 3) and the constraints of the human (Chapter 4). The scissors metaphor emphasizes the need for a single ontology that encompasses both blades: one blade that re±ects constraints of the task situation and a second blade that re±ects constraints on human ability or awareness.
