This is an important model which tries to explain how we solve problems.
An initial process, (the input translation), produces in the problem solver an internal representation of the external environment, at the same time selecting a problem space. Problem solving then proceeds according to the framework of this internal representation – a representation that may render problem solutions obvious, obscure, or perhaps unattainable.
Once a problem is represented internally, the system responds by selecting a particular problem solving method. A method is a process that bears some possibility of attaining a problem solution, as formulated and seen in terms of the internal representation.
The selected method is applied and comes to control the behavior, both internal and external, of the problem solver. At any moment, as the outcome either of processes incorporated in the method itself or of more general processes that monitor its application, the execution of the method may be halted.
When a method is terminated, three options are open to the problem solver:
(a) another method may be attempted,
(b) a different internal representation may be selected and the problem reformulated, or
(c) the attempt to solve the problem may be abandoned.
During its operation, a method may produce new problems – i.e., subgoals – and the problem solver may elect to attempt one of these. The problem solver may also have the option of setting aside a new subgoal, continuing instead with another branch of the original method.