Problem solving by heuristics

Transcript

1. Problems Let's talk about Problems again David @ Oursky
2. Remember?
3. Not that toxic this time
4. Solving a problem Algorithms Heuristics - methods that guarantee solution - mathematical questions - programming - mental shortcuts, rules of thumb that help constrain (simplify) the problem - work well usually, but not always - most of daily life problems
5. • personal factors ◦ cognitive abilities ▪ (e.g., intelligence, memory) ◦ prior experiences, education ◦ personality ▪ (e.g., enjoy thinking? creative?) ◦ thinking style Factors
6. • problem nature ◦ well-defined vs. ill-defined (clear goal?) ◦ static vs. dynamic ◦ complexity • Environmental factors ◦ group task? (social context) ◦ any feedback available? Factors
7. that help us in daily life Heuristics
8. given: 1 out of 100 the group is an engineer Find the engineer
9. 甲，三十歲，已婚，沒有小孩，他能力強，動機高，對自己期許高，廣為同是所。他在 100人中 是工程師的可能性是％？ 乙，四十五歲，已婚，有四個小孩，他保守，謹慎，有進取心。他對政治，社會問題沒有興趣。 閒暇他做公益，解數學題。他在 100人中是工程師的可能性是％？ 丙，沒有任何資料。他在 100人中是工程師的可能性是％？ 下列哪一人有可能是工程師？
10. Representativeness（Kahneman & Tversky，1973） When people rely on representativeness to make judgements, they are likely to judge wrongly because the fact that something is more representative does not make it more likely
11. Q: 摩西帶上方舟的動物，每個種類有幾隻？ 2 ???!!??!?!
12. Fluency heuristic (Jacoby & Brooks, 1984) Moses illusion An issue about how we process input materials Input Process Output Moses, a guy from bible We have mental shortcut too!
13. Fluency heuristic (Jacoby & Brooks, 1984) The more skillfully or elegantly an idea is communicated, the more likely it is to be considered seriously, whether or not it is logical
14. Fluency heuristic (Jacoby & Brooks, 1984) KEY: Fluency this can be involved in - Font style - Layout representation - Graphics - Pace of a speech
15. Fluency heuristic (Jacoby & Brooks, 1984) Life examples - Menu design - A name of a company - Giving guidelines - Speeches of politicians
16. Fluency heuristic (Jacoby & Brooks, 1984)
17. a b c
18. b-a-2c Why you no try a- c ????
19. Mental set The tendency to approach situations in a certain way because that method worked in the past
21. Functional fixedness
22. Functional fixedness (Duncker 1945) A kind of mental set, formed a cognitive structure, limits a person to using an object only in the way it is traditionally used e.g. cup = contains water pencil = writing When tested, 5-year-old children show no signs of functional fixedness. However, by age 7, children have acquired the tendency to treat the originally intended purpose of an object as special (German & Defeyter, 2000).
23. Anchoring Without looking behind, how many bottles are there?
24. Anchoring Q.1 Whether > 20 ? Q.2 Exact number = ?
25. Anchoring Q.1 Whether < 60 ? Q.2 Exact number = ?
26. Anchoring Tversky & Kahneman ,1974 Participants were then asked to guess the percentage of the United Nations that were African nations
27. Spin a roulette wheel
28. Controlled values 10 & 65 Participants whose wheel stopped on 10 guessed lower values (25% on average) Participants whose wheel stopped at 65 guessed higher values (45% on average).
29. Anchoring Another simple example 1x2x3x4x5x6x7x8 vs 8x7x6x5x4x3x2x1 Answer: 40320 Avg. 512 Avg 2250
30. Base rate neglect Airplane accident is more dangerous because of high death rate Fact driving: 1.32 fatal accidents and 1.47 fatalities per 100 million miles airlines: .05 fatal accidents and 1.57 fatalities per 100 million miles - ignore low airplane accident rate - tend to report P(dead l airplane accident) when actually asking for P(airplane accident l dead)
31. Recognition heuristic Do these cities have > 1 million population? Amsterdam London Madrid Munich Paris Riga Sevilla Toulouse
32. Is human rational? Herbert Simon: Bounded rationality - we can not get ALL information needed in real life - bounded by “cognitive limits” (including those we mentioned in Factors) Hence people, in many different situations, seek something that is “good enough”, something that is satisfactory
33. http://www-abc.mpib-berlin.mpg.de/users/ptodd/SimpleHeuristics.BBS/ http://www.eruptingmind.com/thinking-skills-in-psychology/ http://www.socialwork.com.hk/psychtheory/theory_psy/generalpsy/chap10.htm http://www.economist.com/node/13350892 Refs.