steps in problem solving 1.preparation: find and frame problem 2.production: develop good...

Steps in Problem Solving

1. Preparation: Find and frame problem

2. Production: Develop good problem-solving strategies (subgoals, algorithms, heuristics)

3. Evaluate solutions

4. Rethink and redefine problems and solutions over time

©John Wiley & Sons, Inc. 2007 Huffman: Psychology in

Action (8e)

Heuristics vs. algorithms

Heuristics: general problem solving strategies that are often useful but not always effective (in football: control line of scrimmage, avoid turnovers, in chess: control center of board.)

Algorithms: step by step procedures guaranteed to solve a specific problem (recipe to bake a cake, formula to solve for area of triangle)


Action (8e)

Examples of Heuristics 1. Means-end analysis: breaking problem down

into series of sub-problems. 2. Analogies: using past experience as model for

current problem-solving Research on use of analogies (past experience)

contradictory. fixation

- using a prior strategy only

functional fixedness

- fixated on usual functions


Action (8e)

When is past experience harmful?

Dunker (1945) Make a lamp problem.


Action (8e)

Thinking—Five Key Barriers to Problem Solving

2. Functional Fixedness: thinking of an object as only functioning in its usual way

Can you use these supplies to mount the candle on the wall so that it can be lit in a normal way without toppling over?


Action (8e)

Thinking—Five Key Barriers to Problem Solving (Functional Fixedness Continued) To overcome

functional fixedness, think of the matchbox, tacks, and candle all functioning in new ways.


Action (8e)

When is past experience harmful?

Mental set: retaining a old successful problem-solving procedure even though it is not effective in its current context. Water jar example here!


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Experimental testing for mental set: Luchin’s (1942) water jar problem:


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Thinking—Five Key Barriers to Problem Solving

1. Mental Set: persistence in using strategies that have worked in the past

Using no more than four lines, can you connect all nine dots without lifting your pencil from the paper?


Action (8e)

Thinking—Five Key Barriers to Problem Solving (Mental Sets Continued) To overcome

a mental set you must “think outside the box”— literally!


Action (8e)

When is past experience helpful to problem solving?

1. Gick & Holyoak (1980) studies of problems solving with and without past experience

2. Chi’s (1985) studies of expertise and problem solving


Action (8e)

Problem solving in Physics professors vs. students: Problem categorization


Action (8e)

Framing Effects in Problem solving

Imagine that the U.S. is preparing for the outbreak of an unusual…

disease which is expected to kill 600 people. Two alternative programs

have been proposed. Assume that the exact scientific estimate of the consequences of the program is as follows:

If Program A is adopted, 200 people will be saved. If Program B is adopted, there is a 1/3 probability that

600 people will be saved and a 2/3 probability that no people will be saved.

Which of the two programs would you favor?

Imagine the identical situation with the following choices: If program C is adopted, 400 people will die. If program D is adopted, there is a 1/3 probability that nobody

will die, and a 2/3 probability that 600 people will die. Which of the two programs would you favor?

Decision-Making Biases

Confirmation Bias search only for info that supports our ideas

Hindsight Bias report falsely that we predicted an outcome

Availability Heuristic predict probability based on ease of recall

Base-Rate Fallacy ignore info about general principles

Representativeness Heuristic make judgments based on stereotypes

Reasoning mental activity of transforming information to reach

conclusions

inductive reasoning

- driven by data; bottom-up; specific general

deductive reasoning- driven by logic; top-down; general specific

Syllogistic reasoning: premises – conclusion Conditional reasoning: if-then statements used draw

conclusions

Reasoning


Action (8e)

Syllogistic reasoning

Premise: statement assumed to be true for sake of argument, not necessarily empirically true

Premise: All boys are athletes Premise also usually expresses a

relationship between certain concepts, so boys are related to athletes in that all boys are a member of the category athletes.


Action (8e)


Conclusion: to be valid must be necessitated by the premises. Must be only possible conclusion drawn base on relationships expressed in premises.

Conclusion: a valid conclusion cannot just be reasonable or plausible based on premises, it must be necessary.


Action (8e)


P1: All boys are athletes P2: All athletes are muscular C: All boys are muscular

Valid: Use Venn Diagrams to determine.


Action (8e)


P1: All boys are athletes P2: All muscular people are athletes C: All boys are muscular people

Valid?

See website for more reasoning problems


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Conditional reasoning

If: antecedent condition Then: consequent When the antecedent condition is met, the

consequent will occur (no question about it!)

Observation – what condition is actually present

Conclusion: (valid or not valid)


Action (8e)

Conditional reasoning

If she has red hair Then she buys new shoes Observation: she has red hair (affirming

antecedent) Conclusion: she buys new shoes (valid?)


Action (8e)

If she has red hair Then she buys new shoes Observation: she has not red hair (denying

the antecedent) Conclusion: she buys not new shoes (valid?)


Action (8e)

If she has red hair Then she buys new shoes Observation: she buys new shoes (affirming

the consequent) Conclusion: she has red hair (valid?) More conditional reasoning problems at my

website.


Action (8e)

If she has red hair Then she buys new shoes Observation: she buys not new shoes

(denying the consequent) Conclusion: she has not red hair (valid)


Action (8e)

Wason Selection Task

Rule: if there is vowel on one side then there is an even number on the other side of the card


Action (8e)

Abstract reasoning vs. Social contracts reasoning


Action (8e)

Social contracts version of Wason Selection task


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Language

What is language: a symbolic rule-based system of communication shared by a community

Question: can one person have language?

Structure of Language Phonology - basic phonemes (sounds)

Phoneme :smallest unit of speech or sound Morphology - rules for word formation

Morpheme: smallest meaningful unit of language Syntax - rules for combining words to form phrases and

sentences Semantics - meaning of words and sentences Pragmatics - use of language

Note: Grammar includes all these


Action (8e)

Properties of language

1. Arbitrariness: fundamental units of language have arbitrary relationship to what they represent e.g. dog =

2. Generativity = from a set of finite fundamental units, infinite meaning is possible

3. Generational transmission: passed on from one generation to the next


Action (8e)

Properties of language

4. Displacement: can communicate about ideas not in here and now

5. Semanticity: meaningfulness drives all communication


Action (8e)

Studies in Animal Language

A number of species have been studies: dolphins, parrots, whales, etc

Most studies have involved nonhuman apes: Chimpanzees, Gorillas, Bonobos

Why: close relatives of humans, big brains, highly social


Action (8e)

History of Ape language studies

Cross-fostering: raising an ape as a human baby

1950’s Keith and Cathy Hayes: Viki project, teaching a chimpanzee to speak. Big disaster.

Beatrix and Alan Gardner: Washoe project, teaching an ape sign language


Action (8e)


Francine Patterson and Koko: A gorilla learns sign language

Herb Terrace and Nim Chimpsky


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Sue Savage-Rumbaugh and the bonobo Kanzi


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What do apes know about language?

Some elementary syntax Some evidence of displacement 100-200 word vocabulary Use is primarily utilitarian, not for sharing

experience; 90% of Kanzi’s utterances are requests/commands

About at level 2.5 child


Action (8e)

Language Development

Prelinguistic Stage: crying, cooing, and babbling

Linguistic Stage: single-utterances, telegraphic speech, and learning the rules of grammar


Action (8e)

Theories of Language Development Nature Perspective: language is an inborn

capacity that develops primarily by maturation– Chomsky’s language acquisition

device (LAD)

Nurture Perspective: language develops from a complex system of rewards, punishments, and imitation

steps in problem solving 1.preparation: find and frame problem 2.production: develop good...

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