Lecture 8: Problem solving

Question 1

Knowledge-lean problems

Answer 1

• require little knowledge to be solves

- dont have to rely on any knowledge that you already have

Question 2

Knowledge-rich problems

Answer 2

• require a lot of knowledge to solve

- require a lot of knowledge that people already have

Question 3

Well-defined vs ill-defined problems

Answer 3

clear path to solution vs no clear path

Question 4

Behaviourist psychology

Answer 4

Thorndike= learning through trial and error

-random behaviour leads to accidental solution, which would have to be reinforced over a number of trials in order to be remembered

Question 5

Wolfgang Kohler

Answer 5

Mentality of apes (1917)

-study of problem solving in primates

Question 6

Gestalt theory of problem solving

-reproductive PS

Answer 6

=involves the re-use of previous experience to solve a problem (sometimes can be bad for successful PS).

Question 7

Gestalt theory of problem solving

-productive PS

Answer 7

=characterised by insight into the structure of the problem and by productive restructuring of the problem.

Question 8

Gestalt theory of problem solving

-insight

Answer 8

¥ (moment of understanding) often occurs suddenly accompanied by an “ah-ha” experience. It might result from:
¥ Extended unconscious leaps in thinking
¥ Greatly accelerated mental processing
¥ Some kind of “short-circuiting” of normal reasoning process.

Question 9

Functional fixedness

Answer 9

=tendency to use objects and concepts in the problem environment only in their customary and usual way

eg two string problem: struggle to see beyond the function of the paint brush

Question 10

Negative set (entrenchment)

Answer 10

A bias or a tendency to solve problems in one particular way, using a single specific approach, even when a different approach would be more productive

Question 11

Problem-space theory

Answer 11

Newell & Simon – labyrinth (maze) metaphor: problems are solved through exploration of different paths to a solution.

¥ Objective structure of the problem can be characterised as a set of states:
¥ Initial knowledge state
¥ Many intermediate states
¥ Goal knowledge state
¥ Mental operators are actions used to move from one state to another.
¥ There is a whole space of possible states and paths through this space (only some of them lead to the goal).
¥ Representation of all the possible representations
¥ Eg The Tower of Hanoi

Question 12

Problem space theory pt2

Answer 12

¥ Problem-space describes the abstract structure of the problem.
¥ Problem space that have to navigate our way through
¥ For any given problem there are a number of alternative paths from an initial state to a goal state; the total set of such states, as generated by the legal operators is called the basic problem space.
¥ People’s PS behaviour can be viewed as the production of knowledge states by the application of mental operators, moving from an initial knowledge state to a goal knowledge state.

Question 13

Heuristic methods

Answer 13

¥ Heuristics – intuitive strategies to reduce number of states one has to pass through to reach the goal. They are “rules-of-thumb” that do not guarantee a solution, but usually work and save a lot of time.
¥ Algorithms – formal procedure that will definitely solve the problem.
¥ Means-end analysis (example of heuristics):
¥ Note the difference between the current and goal state
¥ Create the sub-goal to reduce the difference
¥ Select an operator that will solve this sub-goal