Problem solving +

Problem solving +

1. Problem solving intro

   • Whenever you have a goal which is blocked for any reason you have a problem - Kahney 1993
   • History - behaviourists (thorndike, Hull) characterised problem solid as trial and error, reproduction of previously learned responses
     • Puzzle box door could not be opened without the cat performing a sequence of actions - Thorndike plotted the time it took for the animal to solve the problem as a function of the number of opportunities
   • History - Gestalt psychologists - characterised problem solving as both reproductive and productive - involves the reuse of previous experience but functional fixedness problem solving set - characterised by insight into structure of problem and restructuring
     • 9 dot problem (scheeret 1963) 9 dots and can't take pen off paper - need to draw 4 lines
       • candle/box of pins thing - Dunker 1945 - easier if worded differently or if box is empty before Ps arrive
       • Lunchins and Lunchins problem solving set - set group = series of problems which could be solve by same complex solution - control group = problems needed different solutions - then test problem - set group used same complex solution - control group used much similar solution - people tend to use longer solution based on familiar strategy
   • Ohlsson - a problem occurs when the problem is represented in a way that does not permit retrieval of the necessary operators or possible actions - the impasse is broken when the problem representation is changed

2. Insight

   • Involves a sudden restructuring of a problem- Ah-ha experience - Metcalfe and Wine records Ps feelings of ;warmth' (closeness to solution' - warmth increased progressively during non-insight problems - with insight problems, warmth ratings remained at same low level until suddenly increasing dramatically just before solution
     • Koler - Gestalt approach - problem was to get bananas that were outside his cage beyond reach of arms - if sultan was given a stick long enough he would immediately use it to reach the bananas - however, if given 2 sticks, neither of which were long enough, we would try then give up and sulk - after a period of time he suddenly went to the poles and placed one inside the other creating a longer pole
       • Ohlssons represnational change theory suggests we need to change the problem representation for insight to occur - this can happen in 3 ways - constraint relaxation - inhibitions on what is regarded as permissible are removed - re-encoding - some aspect of the problem representation are removed - elaboration - new problem info is added to the representation
       • Evaluating Gestalt theory - thought problem solving more than reproduction of learned responses and involves production processes of insight and restructuring - showed that problem solving that related on past experience often led to failure - but insight and restructuring nuclear - informed info - processing approach later

3. Information processing framework

   • Newell and Simon - produced one of first computational models of psychological phenomena - problem space theory of problem solving - problem starts with an initial state - intermediate states - goal state - operators applied to move state to state - numerous alternative states = problem space - people use strategies and knowledge to search through problem space
     • Space-problem theory - Towers of Hanoi transformation problem - well defined - solver given all info needed to solve problem - initial states of problem, goal state of problem , legal operators and operator restrictions
       • state action trees rapidly become very large - searching state action trees is a computationally intractable problem - number of states increases exponentially - people obviously do not solve problems by constructing complete state action trees, and looking for solutions in them
         • If problem solvers think about problems in state-action terms, how do they set about finding solutions? depth first? breadth first? using heuritsic rule of thumb methods
           • Hill climbing - continually try and move from present state to a state nearer goal - need some state evaluation procedure but can take you to a local high - participants preferred move which seemed closer to goal but actually prolonged solution
           • Means-ends analysis - general problem solving strategy - developed by Newell, Shaw and Simon - determine difference between current and goal state - select appropriate operator - sub goal - but in some circumstances can be problematic - can take very long if constantly reevaluating next decision based on last one

4. Analogical problem solving

   • Occurs when we abstract info from a previous problem and relate that to a new problem we are trying to solve - positive transfer - improved performance as a result of solving a number of similar problems - negative transfer - previous experience interferes with the solution to the current problem
     • Towers of Hanoi and Chinese Tea ceremony have identical state space = isomorphic problems
     • Problems with a similar but not identical structure are called homomorphic problems (e.g missionaries and cannibals and jealous husbands)
       • Chinese tea ceremony - transferring duties to more senior guest - complicated - bit like fox and chicken
     • Does experience on a given problem make it easier for participants to solve isomorphic problem? - Luger & Bauer - Group 1 towers of Hanoi - Chinese tea, group 2 in reverse - transfer of learning between tasks
       • Egan and Geeno - tested participants on 5 or 6 ring towers of Hanoi - experimental group had previous experience on 3/4 rings - experimental group showed some benefits
       • Same Q but for homomorphic problems - Reed, Ernst and Banerji - problem 1 = M&C/JH - problem 2 the same but some people told of relationship between 2 problems - data on total no. of moves involves and no. of illegal moves attempted -
         • When problem was the same as their first one they improved, or when they were told the 2 different problems were related, they also improved