ABSTRACT
The greatest part of the burden falls on the cognitive calculation program, the entire undertaking can be implemented in a purely formal system. This chapter suggests that a represented formal model of an agent is ‘pure’ when all new information received by the cognition is given through the sensory channel or channels. SHRDLU is an impure represented formal model of agency because, in addition to the sensory information its camera eye gleans, it receives input in the form of English sentences coming directly from the human operating the program. SHRDLU can perform a wide variety of task instructions. It can respond to instructions to grasp the largest red cube and move it to the right of the smallest blue pyramid, for instance. Terry Winograd’s interest in constructing SHRDLU was in the modelling of the understanding of a natural language. The model world was constructed to give an extension, even if only a formal one, to the semantic concepts.
