Quiz 4

Question 1

These arguments are supposed to raise the probability of their conclusion but fail almost entirely

Answer 1

Fallacies of induction

Question 2

Hasty Generalization

Answer 2

“The food in this town is lousy, judging from this meal.”
“Like, EVERYONE in New York is friendly! Everybody I met was as nice as can be!”
“Man! Old folks around here are terrible drivers! Did you see that old coot passing me on the right??!!”
Talking about the population

Question 3

What is an anecdote?

Answer 3

A story 
Ex: “One time I saw this airplane parked right in the middle of the tarmac in everyone’s way. I asked who it belonged to. Someone told me it was John Travolta’s. Folks, that’s the trouble with these Hollywood liberals. They only care about themselves.”—Rush Limbaugh, paraphrased
“The IRS isn’t interested in the big corporations, just middle-class taxpayers like you and me. I was audited last year—you ever hear of Exxon-Mobile getting nailed?”
“This global warming stuff...what a crock. We had the coldest January on record right here in Columbus last year.”
“ARGUING FROM ANECDOTE” is nothing more than generalizing from a single case or two.
“Anecdotes don’t prove anything.”

Question 4

Small samples

Answer 4

Provide very weak support
Ex: “This Chihuahua bites. Therefore, all Chihuahuas bite.”
When a sample is taken from a homogeneous population, a generalization can be made from the sample.
“This sip of coffee is delicious, therefore all sips of coffee from this cup will be delicious.”

Question 5

A fallacy occurs when a speaker or writer attempts to support a general statement by citing an atypical supporting case

Answer 5

Exceptional cases

Question 6

Biased sample

Answer 6

Basing a generalization about a large heterogeneous population on an atypical or skewed sample.
Example: “Judging from what car dealers say, most business people now think the economy is improving.”
“George W. Bush was really popular in South America. Look at how many people came out to cheer when he went down there.”

Question 7

Self-selection

Answer 7

A Self-Selection Fallacy occurs when generalizing from a sample whose members are in the sample by their own choice.
Example:“Most Americans have a favorable view of the president as a person, judging from an online survey conducted by CNN.”

Question 8

Accident

Answer 8

The Fallacy of Accident occurs when it is assumed that a general statement applies to a specific case even though that case may be an exception.
Example:“Everyone should have access to a college education. Therefore, anyone who applies should be admitted to Cal Poly.”
“This city has a very high crime rate; therefore it will be dangerous to shop in this neighborhood.”
* Fallacy of Accident! To infer from the city’s overall high crime rate, considered in and of itself without regard to anything else, that a particular location in the city has a high crime rate is to commit this fallacy.

Question 9

Weak analogy

Answer 9

Arguments based on debatable or unimportant similarities between things.
Example:“My mom is just like Adolf Hitler. I doubt she will let me go out with you guys.”
“Hey, the ice caps on Mars are melting, and it isn’t due to fossil fuel emissions!! So melting ice caps here aren’t due to fossil fuel emissions either!”
*Earth and Mars are physically similar– a good reason to think ice caps COULD melt on Earth in the absence of fuel emissions. Not a good argument for thinking fuel emissions DIDN’T cause melting here.

Question 10

Appeal to authority

Answer 10

Trying to support a contention by offering as evidence the opinion of a nonauthoritative source.
Example:“My father thinks the president lied. Therefore the president lied.”

Question 11

Appeal to Popularity

Answer 11

Treating an issue that cannot be settled by public opinion as if it can.
Example:“Hondas get great gas mileage. Everyone knows that.”

Question 12

Appeal to Common Practice

Answer 12

Trying to justify a practice on the grounds that it is traditional or is commonly practiced.
Example:“This is the right way. This is the way it has always been done.”

Question 13

Appeal to Tradition

Answer 13

Doing X is a tradition. Therefore it should continue being a tradition.
Example:“Traditionally marriage has been restricted to heterosexual couples. Therefore it’s right to restrict marriage to heterosexual couples.”

Question 14

Bandwagon Fallacy

Answer 14

Similar to the fallacious appeal to popularity.
“You shouldn’t eat at Applebee’s. No right thinking person does.”
The Bandwagon Fallacy plays on our desire to be in step with popular opinion.

Question 15

Post Hoc, Ergo Propter Hoc

Answer 15

Assuming that the fact that one event came after another establishes that it was caused by it.
Example:“After I played poker my cold went away fast. Therefore playing poker caused my cold to go away fast.”
“Every day the sun comes up right after the rooster crows; therefore the rooster causes the sun to come up.”

Question 16

Cum Hoc, Ergo Propter Hoc

Answer 16

Assuming that the fact that one event happened around the same time as another establishes that it was caused by it.
Example:“John had a heart attack while he was saying a prayer. Therefore the prayer caused the heart attack.”

Question 17

Overlooking regression

Answer 17

Example: After a terrible evening with mosquitoes, you wear a copper ‘Mosquito Be-gone’ bracelet. The mosquitoes didn’t seem so bad after that. You conclude that the bracelet works.
[If the average value of a variable is atypical on one measurement, it is likely to be less atypical on a subsequent measurement.]

Question 18

Overlooking random variation

Answer 18

Example:“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.”
[The average length of the drive will vary randomly from test to test.]

Question 19

overlooking reversed causation

Answer 19

Example: “People who walk long distances enjoy good health. Therefore walking long distances will make you healthy.”
[Perhaps being healthy makes people more inclined to take long walks]

Question 20

Overlooking coincidence

Answer 20

Example: “After Susan threw out the chain letter, she was in an automobile accident. Therefore throwing out the chain letter caused her to get in an automobile accident.”
“I got cancer when I lived under a high-voltage power line. Therefore, the high voltage power line caused my cancer.”
“Chimney fires and long underwear purchases increase in frequency at the very same time. Therefore chimney fires cause people to buy long underwear.”

Question 21

Overlooking a common cause

Answer 21

Example: “I left the lights on when I went to bed. Next morning I woke up with a headache. Therefore sleeping with the lights on causes headaches.”
[Perhaps being tired caused both headache and leaving the lights on]

Question 22

Argument by Anecdote (Causal Variety)

Answer 22

It is a fallacy to try to support (or disprove) a cause-and-effect claim by telling a story.
Example:I’ve heard doctors say eating red meat increases your risk of heart disease, but don’t believe it. My uncle lived to be a 100 and ate red meat 3 times a day. He didn’t die of a heart attack.

Question 23

Slippery Slope

Answer 23

A fallacy that occurs when a speaker or writer rests a conclusion on an unsupported warning that is controversial and tendentious, to the effect that something will progress by degrees to an undesirable outcome.
Example:“If we legalize pot, the next thing ya know we will be making meth legal, then heroin—it will never end.”
“Twenty percent? You want to tip her 20%? Hey, next thing you’ll want to tip 25%! And then 30%! It will never end.”

Question 24

Untestable Explanation

Answer 24

Some explanations are vague or circular or not testable even in principle.
Such explanations are said to commit the fallacy of Untestable Explanation.
Example:“He has heart issues because of sins done in a previous life.”
“The attack on the Twin Towers was God’s way of telling us we are sinners.”
“What brought Todd and Brenda together? Fate.”
One thing they have in common: Neither one can be TESTED.
“Men are biologically weaker than women and that’s why they don’t live as long.”—An “expert” quoted in Weekly World News
Some assertions can’t be tested due to their vagueness.

Question 25

Affirming the consequent

Answer 25

Whenever an argument is in this form: If P, then Q.Q.Therefore, P. It is an invalid argument. Ex: If Jane is a member of a sorority, then she is female. Jane is female. Therefore, Jane is a member of a sorority.

Question 26

Denying the antecedent

Answer 26

Whenever an argument is in this form: If P, then Q. Not-P Therefore, Not-Q It is an invalid argument. Ex: If Donald Trump is the Prime Minister of the UK, then he speaks English. Donald Trump is not the Prime Minister of the UK. Therefore, Donald Trump does not speak English.

Question 27

The undistributed middle

Answer 27

When someone assumes that two things related to a third thing are related to each other, as in: All cats are mammals. All dogs are mammals. Therefore, all cats are dogs. Takes several forms: X has features a, b, c, etc.Y has features a, b, c, etc.Therefore X is Y. Another form is: All X’s are Y’s.This thing is Y Therefore, this thing is X. Another form: X is a Z.Y is a Z.Therefore, X is a Y. One other form is: If P is true, then Q is true. If R is true, then Q is true. Therefore if P is true, then R is true. Here is an example of that last form: If Bill wins the lottery, then he’ll be happy. If Bill buys a new car, then he’ll be happy. Therefore, if Bill wins the lottery, then he’ll buy a new car. If P is true, then Q is true. If R is true, then Q is true.Therefore if P is true, then R is true.

Question 28

Contradictory claims

Answer 28

Claims that cannot have the same truth value

Question 29

Contrary claims

Answer 29

Claims that cannot both be true but can both be false