L9_Problem_Solving_07

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Problem solving :Problem solving Problem representation Strategy selection Improvement/Experts Text: Solso, Chapter 15 & pp. 250-259 (on expertise)

Slide 2:Identifying a problem Rarely a topic of cognitive psychology (Gestalt: problem – stems from tension between perception and memory) When a solution is attempted?

Slide 3:Analysis of a problem: Goal state, Initial sate, Operators, Obstacles. Problem space (state space)

State space for the „Tower of Hanoi” problem :State space for the „Tower of Hanoi” problem

Slide 6:Problem representation Representation of all elements of a problem situation. Solution as a redefinition of a problem. Sudden redefinition – insight Obstacles in problem solving Set Functional fixedness Gestalt: tendency to perceive things in terms of their familiar uses Cultural blocks

Slide 7:Strategies for problem solving (paths through a state space): „Brute force” (computational force) Search through a state space which results in finding the shortest way from initial state to a solution Easy to apply; Not always possible: combinatorial explosion (e.g., chess)

Slide 8:Hill-climbing heuristics Choosing the operator which will bring us closest to the goal Working backwards Start from the goal Useful when the end-state is defined more clearly than the initial state. Means-end analysis Note the difference between the current state of the problem and the goal state Form a subgoal that will reduce the difference Select a mental operator that will permit attainment of the subgoal

Slide 9:Solution as representational change Elaboration, Constraint relaxation, Re-encoding -> retrieval of appropriate cues from LTM (Ohlsson, 1992) VI = VII + I; IV = III – I

Slide 10:Problem solving by analogy In science: a computer model of human cognition; a billiard-ball model of gases, etc. Noticing similarities in structure Duncker’s radiation problem

Slide 11:Patient with a malignant tumor in his stomach can only be saved by a special kind of ray. However ray of sufficient strength to destroy the tumor will also destroy the healthy tissue, whereas a ray that will not harm the healthy tissue will be too weak to destroy the tumor. 10% correct solutions A general is trying to capture the fortress, surrounded by a river with 3 bridges, each of them too weak for the entire army to walk through. 40% correct solutions 80% if told that the story was relevant Superficial similarities between problems are important for noticing analogies.

Problem solving by experts :Problem solving by experts Change in problem representation as an effect of knowledge acquisition Differences between experts and novices. De Groot (1946/1965). Research on chess players: Thinking aloud protocols: chess masters did not consider more possibilities nor planned more movements. Reconstruction paradigm: chessboard presentation for 2-15 s. Then: reconstruction of the positions of the figures. Masters: 91% correct, Others: 41%. Fast reconstruction of a chessboard (present): Experts - faster and in meaningful configurations.

Slide 13:Experts work „forward”: Larkin’s (1980) study of physics experts and novices: Experts work on data, drawing inferences; novices work „backwards” Categorization of problems: experts – according to the similarity of solution; novices – according to the surface similarities

Slide 14:Expert problem solving: Perceiving large, meaningful patterns Representing problems at a deeper level (structural) Spending a lot of time analyzing a problem before trying to solve it Good self-monitoring skills Larger knowledge to lean on (also a source for metaphors and analogies)

CREATIVITY :CREATIVITY In problem solving: cognitive activity that results in a novel way of viewing a problem – overcoming functional fixedness, cultural blocks How to measure „creativity” Novelty Usefulness

Slide 16:Measures: Divergent thinking: generating new ideas/solutions Assessed on 4 dimensions: Originality Productivity Flexibility Elaboration Divergence Production Test (Guilford, 1967) Find possible uses for a comb, a button.... Wallas & Kogan test (e.g., objects with wheels) Torrance Test of Creative Thinking (e.g., make this toy more interesting)

Slide 17:Convergent thinking – leading to one solution: assessment: correct/incorrect Insight Test verbal, mathematical, spatial RAT – Remote Association Test Find a logically associated word: (RED, BRIDGE, ANGRY)

Creative ways of overcoming obstacles in problem solving :Creative ways of overcoming obstacles in problem solving Examples of creative thinking techniques: Generating associations, features, features + implications Superposition Problem + random words Personification „A team of small, friendly people”