problem solving 7 Flashcards
what is knowledge lean problems?
require little knowledge to be solved, e.g. puzzles
what are knowledge rich problems?
require a lot of knowledge in order to be solved, e.g. problem solving behaviour of experts
why do we need to combine studies from both rich and lean problems?
in order to gain understanding of p’s beh
well defined problems clear path to solution with initial and goal states clear
ill defined no clear path to solution initial and goal states less precise
what is behaviourist psychology?
- thorndike, learning by trial and error
- hungry cats were placed in a cage with food outside and had to learn how to open the cage
- random beh would lead to accidental solution which would have to be reinforced over a number of trials in order to be remembered
- cumulativenss of learning, lack of insight
- this is an ineffiecient way- should stop and think and try to work it out
what is the early work of Wolfgang kohler?
- mentality of apes
-demonstrated evidence of ‘inisght’ - awareness and thinking- resulting from ‘productive’ problem solving beh
what is gestalt theory of problem solving?
problem solving is both reproductive and productive
reproductive= involves reuse of previous experience
productive = characterised by insight into structure of problem and by productive restructuring of the problem
insight often occurs suddenly accompanied by an ‘ah-ha’ experience. it must result from:
-Extended unconscious leaps in thinking
-Greatly accelerated mental processing
-Some kind of “short-circuiting” of normal reasoning process
-Fundamentally what the Gestalt psychologists referred to as ‘restructuring’
what is functional fixedness?
makes problems hard to solve
tendency to use objects and concepts in the problem environment only in their customary and usual way
what is mental set (entrenchment)?
makes a problem hard to solve
a bias or tendency to solve problems in one particular way, using a single specific approach, even when a different approach would be more productive
what is the problem space by newell and simon?
- labryinth - 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
-operators are actions used to move from state to another
-there is a whole space of possible states and paths through this space
– If we think about a problem- we have a labyrinth to pick our way from the initial state to goal state, we want to achieve
what is the tower of hanoi ?
- can only move one disk at a time
- larger disk cannot be placed om top of a smaller disk
- apply the operators
Problem space for Tower of Hanoi- a number of alternative paths- production of knowledge states by the application of mental operators, moving from an initial knowledge state to a goal knowledge state
what is the problem space?
-Problem-space describes the abstract structure of theproblem
-For any given problem there area number ofalternativepaths from an initial state to a goal state; the total set ofsuch states, as generated by the legal operators is calledthe basic problem space
-People’s PS behaviour can be viewed as the productionof knowledge states by the application of mentaloperators, moving from an initial knowledge state to agoal knowledge state
what is a heuristic?
intuitive strategies to reduce number of stages one has to pass through to reach the goal- rules of thumb- do not guarantee a solution, but usually work and save a lot of time
what are algorithms?
formal procedure that will definitely solve the problem- would involve thinking through all of the problem space
what are means- ends analysis?
example of heuristic
where am I, where do I want to be? - goal state- create a sub goal- select an operator
what did sweller and levine investiagte?
Means-ends analysis proved highly unsuccessful in solving this problem.
Participants who were aware of the end point were far slower than those who were not
what is the availability heuristic?
- coined by tversky and kahneman
- relies on immediate examples that come to mind when making a decision
- occurs unconsciously and operates under the principle that if you can think of it it must be important
- things that come to mind more easily are believed to be far more common and more accurate reflections of the real world
what are problem solving strategies?
- breaking down the problem and generating appropriate sub goals leads to successful problem solving
- experience is one of the main sources of such sub goals- in successive attempts strategies become progressively more efficient
- in order to benefit from our experience we often need to look beyond the surface aspect of the problem
what are isomorphic problems?
- formal structure is the same, but their contents differ- they can have the same form or the same relational structure
- even slight differences in presenting the problem may lead to a decrease in success- different surface charactersitics tend to obscure underlying structural isomorphism
why is the rule application hypothesis?
-Predicts ‘move’ version easier than ‘change’ version
-‘Change’ version twice as hard as the ‘move’ version
-Change rules are harder to apply (require morethinking about the ‘legal’ operations) than ‘move’ rules
what are the rule learning hypothesis?
kotovsky, hayes and simon
General ease of rule learning and application is likelyto be influenced by:
-Consistency with real-life knowledge
-Memory load inherent in the problem
-Ease of representing rules with mental imagery
Kotovsky et al. (1985) found that it took participants longerto simplylearnchange rules compared to move rules
how to overcome problem solving obstacles?
- working backwards
-finding an analogy
-restructuring - creative thinking
what is working backwards?
-starting with a goal state and seeking the path back
- effective when one doesnt know how to reach a goal, or doesnt understand a problem structure
-more used by noices than experts
what does using analogies do?
Relies on using similarities with problems solved inthe past. Detecting similarities is not always easy.
what is superficial similarity?
Solution irrelevant details arecommon in two problems
what is structural similarity?
Causal relationships among maincomponents are shared by two problems
what is procedural similarity?
Actions for turning the solutionprinciple into concrete operations is common for twoproblems
what is restructuring?
-Looking for alternative ways to conceptualise theproblem
-Breaking the mentalset
-“Thinking outside the box”
-Insight
what is creative thinking?
use of analogy is common here
George de Mestral in 1948 examined why it is that burrs stick to clothes so readily
his creativty led to his invemtion
what are good things about research on puzzles?
-Gives us a normative theory that deals with “ideal”behaviour and can help us evaluate “normal”behaviour.
-As puzzles are well defined problems behaviour can beformalised and implemented in a computational model(application in AI).
-Advances our understanding of basicproblem solvingprocesses (representations, learning, etc.).
-Allows integration with models of other cognitiveprocesses (e.g. memory)
what are limitations of research on puzzles?
-Ecological (or external) validity
-Puzzles are unfamiliar problems about which we have littleknowledge
-Knowledge required for the solution is present in the puzzle
-Requirements in puzzles are relatively unambiguous
-Puzzles are well defined problems with operators, initialand goal state well specified
-In life we often deal with ill-defined problems that areunder-specified and require domain-specific knowledge.
