Flashcards
PHL1005A_Inductive Logic
Flashcards do conjunto (31)
- 1What is INDUCTIVE LOGIC?the study of inductive arguments
- 2In what way do inductive arguments differ from deductive arguments?- the premises don't entail the conclusion, but only make it more likely
- they are risky
- they are ampliative
- they are not assessable usig mechanical rule (must draw on background knowledge) - 3What are Inductive Arguments called in matters of degree?"strong and weak"
- as opposed to valid/invalid (absolutes) - 4What does Probability Theory have to do with Inductive Logic?central to inductive logic although in itself strictly deductive (... making conclusion more probable...)
- 5What does Pr (A) mean?symbolises the probability of A being true where A is a proposition
- 6On what scale are probabilities ranked and what do they mean?- scale of O to 1
- O is "certain to be not true"
- 1 "certain to be true" - 7How do you work out the probability of A or B, where A and B are mutually exclusive?Adding probabilities:
Pr(A or B) = Pr(A) + Pr(B) - 8How do you work out the probability of A and B, where A and B are independent?Multiplying Probabilities:
Pr(A&B) = Pr(A) x Pr(B) - 9What does Independence mean as a concept in Probability?two events are said to be independent if one has no influence on the other
- e.g. one spin of roulette wheel has no influence on next spin - 10How do you work out the probability of A given B?Conditional Probabilties:
you must divide A and B by probability of B
Pr(A/B) = Pr(A&B)/Pr(B) - 11What is Pascal's Wager (developer of Probability Theory)?Life of virtue + God exists = infinite gain (heaven)
Life of virtue + God doesn't exist = finite loss (boring life)
Life of debauchery + God exists = infinite loss (hell)
Life of debauchery + God exists = finite gain (fun life) - 12What is INDUCTION?reasoning from previous experience
- 13What does "population" refer to in inductive logic?all members of a class
- 14What does "sample" refer to in inductive logic?some or one member of a class
- 15What are the three broad types of inductive interferences?1. From sample to population
2. From sample to next member
3. From population to sample - 16What type of inductive interference is this? -> I've tried 5 apples from the bag, 4 were good, so 80% of the apples in the bag are good.From sample to population
-> most common - 17What type of inductive interference is this? -> I've tried 5 apples from this bag, 4 were good, so the next apple is 80% likely to be good.From sample to next member
- reducible to sample-to-population inferences - 18What type of inductive interference is this? -> 80% of the apples in this bag are good, so this one is 80% likely to be goodFrom Population to Sample
- 19What is important when making an induction from sample to population?- sample must be reasonably large - the larger the sample, the smaller the deviation (Law of Large numbers)
- sample must be representative, i.e. identical in respect of the feature in question to the population from which it's drawn (e.g. randomize sample) - 20What is important when making an induction from population to sample?problem with Bayes Theorem
- from different aspects of individual I can infer e.g. probability of liking Beethoven
-> but is there a way of getting from individual probabilities to "all-things-considered" probability of liking Beethoven? - 21What are some of the most common fallacies we make when it comes to inductive reasoning?- The Conjunction Fallacy
- Gambler's Fallacy
- Estimating Coincidences
- Generalising from a small sample
- Generalising ffrom a unrepresentative sample
- Self-selecting polls
- P conditional on Q is not the same as Q conditional on P
-Base-rate fallacy
- Confusing Correlation and Causation
- Confirmation Bias - 22Which fallacy of inductive reasoning is this? -> most people believe the reverse but probability of two propositions A and B both being true is Pr(A) being true times Pr(B) being trueThe Conjunction Fallacy
- A & B is less likely to be true than either A or B on their own - 23Which fallacy of inductive reasoning is this? -> believing that probabilities that are in fact independent are in some way dependent, e.g. bad luck will be balanced out by good luckGambler's Fallacy
- 24Which fallacy of inductive reasoning is this? -> people are prone to underestimate coincidences, interpreting things as miraculous, spookyEstimating Coincidences
- 25Which fallacy of inductive reasoning is this? -> generalising from a sample of <400Generalising from a small sample
- 26Which fallacy of inductive reasoning is this? -> generalising from unrepresentative sampleGeneralising from unrepresentative sample
- randomisation - 27Which fallacy of inductive reasoning is this? -> generalising from polls which only volunteers take part in (not representative of population as a whole)Self-selecting polls
- 28Which fallacy of inductive reasoning is this? -> Chance of an Exeter student being British is 4/5; chance of a British student being at Exeter is much smallerP conditional on Q is not the same as Q conditional on P
- 29Which fallacy of inductive reasoning is this? -> not taking into account Pr(P) on its own (base-rate) when estimating probability of P given some evidence EBase-rate fallacy
- if base-rate is very low, it is unlikely that E will make much difference - 30Which fallacy of inductive reasoning is this? -> assuming P causes Q when P and Q are correlated, i.e. often occur togetherConfusing Correlation and Causation
- Q might cause P
- they might both be caused by some third thing R - 31Which fallacy of inductive reasoning is this? -> having a hypothesis/belief and focusing on evidenceto confirm it; ignoring evidence that goes against itConfirmation Bias
-> how stereotypes are perpetuated in the face of contradictory evidence
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- Philosophie (PHL1005A_Evidence and Argument) FlashCards sobre PHL1005A_Inductive Logic, criado por Cat Fischer em 20-12-2017.
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- Cat Fischer
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