goal
A desired state; provides the direction for problem-solving behavior.
subgoal
A goal undertaken in the service of another goal.
operator
An action that changes one problem state into another.
protocol analysis
Based on transcripts of subjects asked to "think aloud" while solving problems.
problem space
The set of possible states that could be generated by applying all available operators to the current state, repeating for all the resulting states, and so on until the goal state is reached.
initial state
Representation of the situation at the start of solving a problem.
current state
Representation of the present situation in a problem solving task.
goal state
Representation of the desired situation in a problem-solving task.
solution path
A sequence of states through a problem space leading from the initial state to the goal state.
production rule
Represents operators in the form of condition-action rules.
exhaustive search
Searching for a goal state by generating the entire problem space
difference reduction
A problem solving strategy in which operators are selected to decrease the difference between the current state and the goal state.
means-ends analysis
A problem solving strategy in which blocked operators lead to the creation of new subgoals.
functional fixedness
A tendency to see the conventional uses of familiar objects, and to fail to see novel uses.
set effects
A tendency to continue using a familiar procedure to solve new problems, which may interfere with discovering more efficient procedures.