ABSTRACT
As these opening quotes suggest, the pioneers of early work on human information processing and problem solving fully appreciated the signi¤cance of the task environment. As suggested in Chapter 2, this follows naturally from Shannon and Weaver’s (1963) theory of information that it is essential to situate any action or decision into the larger context of possibilities. In Newell and
Simon’s (1972) work, this involved describing the “states” (including the initial and goal states), the “operators” that allowed movement from one state to another, and the “constraints” (i.e., rules) on application of those operators.
