PSY270 Lecture 11
* read the chapter summary
Problem – is difficult (obstacle between present state and goal), solution is not immediately obvious.
Well-def ined: usually have a correct answer, procedures that will lead to a solution
Ill-defined: does not have one cor rect answer, path to solution is unclear.
Gestalt approach: problem solving as representation and restructuring NOT IN FINAL, just read it
refers the Gesalt psychologists (chapter 3)
ohow people represent a problem in their mind
ohow solving a problem involves reorganization or restructur ing of this representation
believed success in solving problem depends on representation of problem
orestructure problem insight.
oExamples: the candle problem, two-string problem
Participants restricted functions of object (functional fixedness)
“Mental set” – preconceived notion about how to approach a problem, determined by past experience
M e ntal s e t inf l uenc e d p ro b lem solvin g .
Solvin g a p ro b lem o f t en in v o lve s cre a t i ng a n ew repre s e ntat i on ( r e s t r uctur i n g )
Modern research on problem solving: the information-processing approach
Newell and Simon’s approach
s a w p ro b lems in terms o f an initial state an d a goal state
oTower of Han o i p ro b lem (3 d is c s sta c ked o n lef t p eg)
Ill ust r ate s me a ns-en d analysis
Pro b lem solving is ap p l i c a ble to re a l lif e.
TermDescriptionExample from Tower of Hanoi
Initial stateConditions at beginning of problemAll 3 discs on left peg
Goal stateSolution to problemAll 3 discs on right peg
Conditions after each step is made toward solving a problemAfter moving the small disc to the r ight peg,
there are two other discs on the left
Operators Actions that take the problem from one state to another.
Governed by rules
Rule: A larger disc cannot be placed on a
Problem space All possible states that could occur when solving a problemPossible solutions (p. 334 figure 12.11)
A way of solving a problem in which the goal is to reduce the
difference between the initial and goal state.
Establishing subgoals, each of which moves
the solution closer to the goal state.
SubgoalsSmall goals that help create intermediate states that are closer to
the goal. Occasionally, subgoal may appear to increase the
distance to the goal state but in the long run c an result in the
Subgoal 4: free up the medium sized disc,
need to move small disc from middle peg back
to peg on left.
This ap p roa c h to p ro b lem solvin g p ro v ided a way to spe c i f y the p o s s ible p athways f r om ini t i al to g o al state
* M a ter i al af t er Newel l & Si m on not in le c ture sl i de s , b u t i m p o r t ant to re a d . ( r e a d sum m ary)
Problem is difficult (obstacle between present state and goal), solution is not immediately obvious. well-defined: usually have a correct answer, procedures that will lead to a solution. Ill-defined: does not have one correct answer, path to solution is unclear. Mental set preconceived notion about how to approach a problem, determined by past experience and knowledge. me n t al s e t influ e n c e d p r o bl e m s olvin g. Modern research on problem solving: the information-processing approach. Illu s t r a t e s m e a n s-e n d a n alysi s. Pro bl e m s olvi n g is a p plic a bl e t o r e al life. Conditions after each step is made toward solving a problem. Actions that take the problem from one state to another. All possible states that could occur when solving a problem.