Dependability of Joint Human-Computer Systems

Human-computer systems have traditionally been analysed and described in terms of their components n humans and computers n plus the interaction. Several contemporary schools of thought point out that decomposed descriptions are insufficient, and that a description on the level of the system as a whole is needed instead. The dependability of human-computer systems must therefore refer to the performance characteristics of the joint system, and specifically the variability of human performance, not just as stochastic variations but also as purposeful local optimisation.