Effective Variety? for whom (or what)? A folk theory on interface complexity and situation awareness

Complexity is concept that is typically used to describe the size or composition of a system and its constituent components. The cybernetics community has long recognized the need for complexity, understanding that only the variety of a system can destroy the variety of the environment and inputs to the system. Conversely, the applied psychology and decision making communities generally acknowledge that increased complexity degrades decision making performance in dynamic tasks through several mechanisms. A notional model of “Effective Variety” is discussed, which states that there is an optimal level or range of complexity for any human-machine interface that will facilitate optimal dynamic decision making performance in a human-machine team. This initial paper discusses a concept and model of Effective Variety, and focuses specifically on how interface complexity affects Situation Awareness (an antecedent to decision making performance), and areas for future research into such a theory.