week 1: problem solving Flashcards
Define problem solving
“the process of constructing and applying mental representations of problems to finding solutions to those problems”
Define problem
a situation in which there is a discrepancy between the current state of the world and a goal state
Wessels stages in problem solving (DDEE)
- Define the probelm
(what is the goal state, current state, available actions) - Devise a Strategy
(select an action that will bring the current state closer to the goal state) - Execute the Strategy
(carry out the intended actions) - Evaluate progress towards the goal
(measure the distance between the goal and current state, and how it has changed)
What makes problem solving easy or hard
- distance between goal and current state
- difficult problems require more actions taken
- easier to solve a problem when there are fewer pssoble actions to search through
- expertise in a domain also affects the ease of problem solving
- some problems are solvable, some are not
What makes a problem well defined
all aspects are clearly specified
1. current state
2. goal state
3. available actions
but well defined problems are not always easy to solve or solvable
What makes a problem ill defined
not clearly specified information about current or goal state, or the available actions
The role of insight in problem solving
As Wessels four stages are not run through consciously, the solution comes to us in a flash of insight
eg crosswords, anagrams, and lateral thinking puzzels
Mental representation in problem solving
The way that our beliefs, knowledge, and memories are stored within our minds
- it is a representation of SOMETHING which stands for the corresponding information of the external world
- a mental representation of a problem is our knowledge about its different components (current, goal, available actions)
- can be wrong, inaccurate, or missing information
- solving a problem depends on finding appropriate mental representations of that problem
Functional fixedness
A mental block against using an object in a new way that is required to solve a problem (narrow mental rep)
- less strong in children cf adults
- decreased ff is a marker of creative thinking
- increased functional fixedness may be useful when problem solving requires using an object in a standard way
How to reduce functional fixedness
- if individuals are trained using objects in different ways
- placing unusual or nonsense labels on objects encourage people to think of alternative uses
- asking participants to list alternative uses for objections
Available actions: Ways of devising and executing a strategy
Algorithm vs Heuristic
Algorithms
A procedure guaranteed to find the solution for the problem, often being characterised as a set of steps and stopping condition
- only exist for some types of problems but no universal problem solving algorithms
Heuristic
Is a rule of thumb that is easy, fast and often helpful
- no guarantee that a heuristic will produce a solution as it may make things difficult depending on the problem
- learned from experience
Generate test Heuristic
Repeatedly generating a possible solution and testing to see whether that solution is correct
- useful if search space is small (set of possible solutions)
- useful if there is no way of measuring how close the current state is with goal state
Difference reduction heuristic
To take whatever action produces the greatest reduction in the difference between the current state of the world and the goal state
Creating subgoals
An intermediate state between the current state and the goal state
- Creating numerous subgoals effectively break up a big problem into a series of smaller problems
- may not be useful for ill defined problems
- can stop you from solving the original problem if the subgoals arent suitable
- care must be taken with non-independent subgoals with ithe order it is carried out
Means end analysis
identifying various ends and consdering what means are available to achieve each
Newell and Simon theory of human problem solving
problems are broken into subgoals by using the difference reduction heurstic to solve each subgoal
- when the preferred strategy is blocked, we remove them so it temporarily becomes the end
Incubation
taking time away from solving a probelm can help people find a solution
- helps for insight porblems, which depend on a single key insight
- helps overcome a bias towards repeat state avoidance
