Chapter 12 Flashcards
Researchers compare problem solving to a search, what are the 3 components of that search?
Initial state: Knowledge adn resources you have at the outset
Operations: Actions that can change your state
Path constraints: limited time or money rule out certain solutions
What is the problem space?
The set of all states that can be reached in solving this problem
What is the “brute force” approach
tracing through the entire problem space exploring each branch – guarantees you’d find a solution, but at the same time it’s hopeless because there are infinite options for most problems ie. chess
What is the hill climbing heuristic? What’s it’s limitation?
at each point simply choose the option that takes you in the direction of your goal
limitation: Often problems require you to breifly move away from your goal and only from this new position can it be solved ie. rubics cube
What is the means-end analysis heuristic?
compare your current state to the goal state and ask “what means do I have to make these more alike?”
- involves breaking your problems into subproblems each with their own goal (some regard subproblems as a heuristic of it’s own)
How can pictures help solve problems? What’s better mental images or pictures?
- visualizing can be advantageous to algebraic solutions
sometimes mental images are preferable: for example moving pictures are easier to depict mentally than with a diagram - pictures can be better for elaborate or detailed forms because a picture gives you a fresh start and possible new perspectives
called “externalizing” and is easily demonstrated in the lab and the real world
How can analogies be used to solve problems? (tumor/fortress example) What does this mean is importnat in analogy use?
only 10% of those given the tumor problem without an analogy solved it
if given an analogy with the tumor problem 30% solved it
Finally an anology with a hint that it could be useful lead 70% to solve it
> it means people benefit from analogies when suitably instructed
Why is spontaneous use of analogies so rare?
1 reason is faulty memory search for things related to the surface structure of the problem (things I know about tumours) and instead think of the principles governing the problem ie its underlying dynamic or “deep structure”
2. People can only use an analogy if they realize how it maps on to the problem being solved
How can we manipulate peoples use of analogies (2 experiments)
You can improve problem solving by encouraging people to pay attention to a problems underlying dynamic
1. subjects told to either solve practice problems one by one or to compare, the latter forced them to look at underlying dynamic and that group was more likely to use training problems as analogies
- one group told to memorize problems, another told to understand them. The understand group later solved 90% of test problems while the recall group only got 69%
How do experts solve problems
- They think about problems in terms of deep structure
ie. experts sort physics problems according to physical principles of the problems solutions while notcies sort according to surface features (like subject of the problem) - Experts are more likely to use analogies but only in their relevant domain - there was no relation b/w physics experts and analogy use in verbal SAT scores
- also in real world discussions experts employ analogies often - chunking and subgoals
Why can chess experts recreated boards after only viewing them for 5 seconds
Because they break the pieces into subgroups relating to strategies. If the pieces are laid out randomly they have no memory advantage
What does it mean that experts use perception of higher units?
they focus on the units and how they relate to eachother, they set subgoals for each unit.
- higher order units lend strcture to the experts thinking and guide them in choosing the next move
Can novices be taught to think in terms of higher order units?
Yes, in one study groups received set of mathematical procedures either with or without labels (which highlighted the function of each step). Label group was better able to use this new procedure in solving new problems
Are these strategies all that makes an expert?
No - they also have much more knowledge and have recieved feedback and instructions that imrpove their performance. Experts also organize their knowledge more effectively
- one study indicated experts use more cross referencing meaning…,
meaning all information has associations with echo other = experts have better access to what they know
