Chapter 7 Flashcards
Hasty Generalizations
Arriving at a general statement or rule by citing too few supporting cases.
Generalizing from too few cases or from samples that are too small
Example: The food in L.A. is lousy, judging from this meal
Arriving at a general statement or rule by citing too few supporting cases
Hasty Generalization
Example: The food in L.A. is lousy, judging from this meal
Fallacy of the Lonely Fact
Another word for Hasty Generalization
Argument by Anecdote
When a speaker or writer tries to support a general claim by offering a story. A version of hasty generalization.
Example: Did you read where John Travolta flew his plane into LAX and parked it on the tarmac - right out there in everyone’s way? That’s the trouble with these Hollywood actors. They don’t care about anyone but themselves.
Supporting a claim by offering a story
Argument by Anecdote
Fallacy of Small Sample
type of hasty gneeralizatio. When someone tries to derive a statement about all or most members of a population from a statement about a tiny sample of the population.
Example: People who live in Cincinnati have no idea where Akron is. I didn’t, when I lived in Cincinnati.
Example: Things cost less at Costco. I bought lawn fertilizer there for a ridiculously low price
People who live in Cincinnati have no idea where Akron is. I didn’t, when I lived in Cincinnati
Fallacy of small sample
Things cost less at Costco. I bought lawn fertilizer there for a ridiculously low price
Fallacy of small sample
Generalizing from exceptional cases
Arriving at a general statement or rule by citing an atypical supporting case
The police aren’t required to get a search warrant if they arrest a supsect while a robbery is in progress and search him for a weapon. Therefore, they shouldn’t be required to get a search warrant for any kind of search
Generalizing from Exceptional Cases
Animals will live longer if they are on a calorie-restricted diet. This has been shown in experiments with rats
Generalizing from Exceptional Cases
Fallacy of BiasedSample
A type of generalizing from exceptional cases
Almost everyone in a large survey of Tea Party members thinks the president should be impeached. Therefore, most Americans think the president should be impeached
Fallacy of Biased Sample.
The problem isn’t that the survey is small, but that Tea Party members might have atypical opinions
Judging from what car dealers say, most business people now think the economy is improving
Fallacy of Biased Sample.
Car dealers see the economy from their own perspective
Self-Selection Fallacy
version of generalizing from an exceptional case.
Occurs when someone generalizes incautiously from a self-selected ample. A self-selected sample is one whose members are included by their own decision.
Example: Most Americans have a favorable view of the president as a person, judging from an online survey conducted by CNN
Most Americans have a favorable view of the president as a person, judging from an online survey conducted by CNN
Self-Selection Fallacy. The opinions of respondents to an online survey select themselves into the sample by their own decision.
Fallacy of Accident
When a speaker or writer assumes that a general statement automatically applies to a specific case that is (or could be) exceptional
It is illegal to use a cell phone while driving; therefore, that police officer committed a crime when she used her cell while driving
Fallacy of Accident.
The general statement that it is illegal to use a cell phone while driving does not automatically apply to the special circumstance mentioned. It is easy to imagine situations where official business might best be conducted on a cell.
Everyone should have access to a college education. Therefore , anyone who applies should be admitted to Cal Poly
A general rule is being applied here to an exceptional case. Fallacy of Accident
In this country we have a right to free speech. Therfore, if I want to threaten the mayor, that is my right
Fallacy of Accidnet
Costco sells for less. Therefore, lawn fertiilizer will cost less at Costco
Fallacy of Accident. The fact that Costco in general sells for less raises the probability only slightly that it will sell this specific item for less
The city has a very high crime rate; therefore, it willbe dangerous to shop in this neighborhood.
Fallacy of Accident. It would be a hasty generalization to draw a conclusion about a city’s overall crime rate from what you observed in one particular location. It is also the fallacy of accident to infer from the city’s overall high crime rate, that a particular location in the city has a high crime rate.
Weak Analogy
Sometimes called false analogy.
A weak argument based on debatable or unimportant similarities between two or more things.
Example: My mom is just like Adolf Hitler. I doubt she will let me go out with you guys.
Mistaken appeal to authority
Supporting a contention by offering as evidence the opinion of a nonauthoriative source
Example: My father thinks the president lied. Therefore, the president lied.
Mistaken appeal to popularity
Also called mistaken appeal to common belief.
When a speaker treats an issue that cannot be settled by public opinion as if it can
Exmaple. The Iranians have nuclear weapons. Everyone knows that
Mistaken apeal to common practice
Sometimes calls mistaken appeal to tradition
justifying a practicce on the grounds that is traditional or is commonly practiced.
Example: This is the right way; it’s the way it has always been done.
Bandwagon Fallacy
By mentinoing the popularity of a proposition, a speaker or writer may not be trying to offer evidence of its truth. Instead, he or she may be dangling a psychological inducement to believe it.
Example: Hillary Clinton has earned your support. Everyone is endorsing her.
Post Hoc, Ergo Propter Hoc
“After this, therefore because of it”. Assuming the fact that one event came after another establishes that it was caused by the other
Example; After I took Zicam my cold went away fast. Therefore taking Zicam caused my cold to go away fast.
Correlation does not prove causation
True
Overlooking the possibility of coincidence
A special case of the post hoc fallacy. Overlooking the possibility that the sequential events were coincidental
Example: After Susan threw out the chain letter, she was in an automobille accident. Therefore throwing out the chain letter caused her to get in an automobile accident
OVerlooking a possible common cause
Post hoc fallacy
Example: I left the lights on when I went to bed. Next morning I woke up with a headache. Therefore leaving the lights on caused the headache.
LEaving the lights on and waking up with a headahce may be the effects of a common cause, such as having gone to bed unusually tired or intoxciated
Overlooking the possibility of random variation
post hoc reasoning.
Ignoring the fact that values or variables fluctuate randomly
In our tests, we asked randomly selected men to drive a golf ball as far as they could. We then had them wear our magnetic bracelet and try again. On the second occasion, the men hit the ball an average of ten feet further. Our bracelet can lengthen your drive as well.
Improvement might simply have been due to random variation. If performing the test again, the average drive length might decrease.
Overlooking the possibility of regression
If the average value of a variant is atypical on one measurement, it is likely to be less atypical on a subsequent measurement.
Example: We measured the IQs of a group of students and found the average to be relatively low. Then we had them take a course in criticla thinking, after which we measured their IQs again. THeir IQs were higher. THerfore the course in critical thinking raised their IQs.
Average IQs were apt to be higher on the second measurement (closer to the true average)
Cum Hoc, Ergo Propter Hoc
“With this, therefore because of it” Assuming that the fact that tow events happen at about the same timeestablishes that one caused the other.
Example: John had a heart attack while saying a prayer. Therfore the prayer caued the heart attack.
Untestable Explanation
When someone offers an explanation that could not be tested even in principle
Example: He has heart issues because of sins done in a previous life.
Weak Analogy
Offering an argument based on debatable similarities between two or more things