clare 4

• what is a problem

  when it is not clear how to get from the start state to goal state
• cheap necklace problem


  4 chains with 3 links each

  • Need to make 1 chain

  • 2 cents to open link

  • 3 cents to close link

  • You have only 15 cents

  
  

  This problem is difficult for many people because they tend to adopt an inappropriate mental set to approach this problem
• types of problems


  well defined and ill defined problems

  
  

  knowledge lean and knowledge rich problems
• well defined problems


  problems in which the initial state, the goal, and the methods available for solving them are clearly laid out

  
  

  eg chess
• ill defined problems


  Start state or end state or the possible strategies may be unknown

  
  

  eg exams
• knowledge rich problems


  Problems that require specific knowledge

  
  

  eg medicine
• knowledge lean problems


  problems that can be solved without the use of much prior knowledge

  
  

  eg puzzle
• behaviourist approach


  trial and error learning

  Thorndike's cat experiment

  - unsystematic

  - no knowledge

  - slow

  - doesn't work for all problems
• Thorndike's cat experiment (1898)


  puzzle boxes from which cats could escape by pulling a lever to open a door and gain access to food outside the box

  
  

  random behaviours at start but eventually, through trial and error, would perform the correct action
• Gestalt approach


  Success in solving a problem is influenced by how it is represented in the mind

  
  

  involves insight, aha moment
• problem restructuring (gestalt)


  restructure or reorganize their representation of the problem, notice relevant information not previously noticed, switch strategies

  
  

  Koehler's (1925) monkey experiment show problem is solved after an incubation period
• functional fixedness (gestalt)


  the tendency to perceive an item only in terms of its most common use

  
  

  Duncker's (1945) candle problem - fix and light candle on a wall so wax doesn't drip on table, pin box and place candle inside
• problem solving and insight (gestalt)


  maier (1931) two string problem

  attach scissors to end of rope and create pendulum to reach second

  
  

  facilitated by unconscious hints, researcher would move rope by accident
• neuroscience and insight


  activation in right anterior superior temporal gyrus

  
  

  fMRI - becomes more active when individuals experience insight

  
  

  EEG - distinctive peak in brain activity just before moment of insight, shows neural signature that precedes conscious realization of solution
• gestalt approach evaluation


  Recognises the role of insight

  
  

  Mechanisms underlying insight are not specified
• representational change theory


  explains processes underlying insight:

  - construct problem representation

  - retrieve moves (operators) by spreading activation from problem rep

  - impasses occur when problem rep doesn't cue right operators

  - impasses broken by restructuring problem rep

  - once impasse is broken an insight may occur
• problem representations can be changed by

  - changing the representation of the problem

  
  

  - relaxing the constraints on what moves are allowed
• changing the representation of a problem


  changing the way you think about the problem

  
  

  board has 62 squares, can you cover whole board with 31 dominos?

  (no because there's two black squares taken away, need red and black)
• relaxing the constraints


  assume anything is possible

  
  

  move one matchstick so equation is correct
• representational change theory evaluation


  explains some of the mechanisms underlying insight

  
  

  doesn't explain what leads to representational change or why incubation helps
• information processing approach


  computational modelling approach -

  general problem solver

  
  

  most problems don't require insight, focus instead on knowledge lean problems
• general problem solver (info processing approach)


  problem solving is a search through the problem space (all possible states of a problem)

  
  

  we don't have WM capacity to think of all possible moves, use general purpose heuristics instead
• heuristics (general problem solver in info processing approach)

  forward search (from current state to future)

  
  

  backward search (from goal to current state)

  
  

  avoid loops (new solutions over previous paths)

  
  

  hill climbing (actions that move you closer)

  
  

  means-end analysis (sub-goals)
• information processing approach evaluation


  - Works well for well-defined problems

  - Good objective measures of how well people perform

  - Led to well-specified computer models

  
  

  - Many everyday problems are ill-defined

  - Doesn't work for insight Problems
• analogical problem solving


  we learn from past problems/ experience

  
  

  negative transfer - functional fixedness

  
  

  positive transfer - near transfer to similar context and far to different context

  
  

  learn from analogy using surface features and structural features
• analogical mapping - (Gick and Holyoak 1980)


  1. gave the radiation problem with no analogy 10%

  2. If you gave the fortress problem and solution 30%

  3. Tell them fortress will help you get it right 70%
• analogical problem solving evaluation


  - Retrieving analogies is hard unless the problems share similar surface features

  
  

  - In real life, this may be even more difficult because the time and context may be more distant than in lab studies

  
  

  - Individual Differences not well understood
• expertise


  focus on problems that depend on extensive knowledge and learning

  
  

  have a lot of knowledge that can be accessed quickly

  
  

  more automatic process
• chess expertise (DeGroot 1965)


  grand masters considered more moves and took less time to move with move rating of 8.2

  
  

  experts considered less moves, took more time, and had move rating of 5.2

  
  

  chess masters recalled 91% of 5s board presentation, experts 43%
• medical experts (Melo et al 2012)


  medical experts fast at detecting tumours (~1 sec)

  
  

  activates same brain areas as object recognition

  
  

  experts use fast and automatic processes which develop with practice
• Theories of Problem-Solving:  


  Behaviourist Approach, Gestalt Approach, Problem Restructuring, Information Processing,  Analogical Problem-Solving