conditional reasoning

Ms. Sandstrom's newspaper column describing a strange natural phenomenon on the Mendels' farm led many people to trespass on and extensively damage their property. Thus, Ms. Sandstrom should pay for this damage if, as the Mendels claim, she could have reasonably expected that the column would lead people to damage the Mendels' farm.

WHATS THE JUSTIFYING BRIDGE?

actions caused trespass AND she could have reasonably expected this → she should pay for damage

If the city starts requiring residents to sort the materials that they put out for recycling, then many residents will put more recyclables in with their regular garbage. This will result in more recyclables being buried in the city's landfill. However, because of the cost of having city workers do the sorting, the sanitation department will not stay within its budget unless the sorting requirement for residents is implemented.

stay within budget → require residents to sort recycling → some residents will put MORE recycling in their garbage → MORE recyclables will be buried in city landfill

If this parking policy is unpopular with the faculty, then we should modify it. If it is unpopular among students, we should adopt a new policy. And, it is bound to be unpopular either with the faculty or among students.

/modify → /unpop with faculty → unpop with students → adopt new

---

unpop with faculty → modify

unpop with student → adopt new

/unpop with faculty → unpop with students

A gift is not generous unless it is intended to benefit the recipient and is worth more than what is expected or customary in the situation; a gift is selfish if it is given to benefit the giver or is less valuable than is customary.

/ben recip OR /worth more → /generous

ben giv OR worth less → selfish

Pollution is a problem wherever there are people who are indifferent to their environment, and nature's balance is harmed wherever there is pollution.

indifferent → pol problem → balance is harmed

It is clear that what is called "health education" is usually propaganda rather than education. Propaganda and education are never the same thing. The former is nothing but an attempt to influence behavior through the repetition of simplistic slogans, whereas the latter never involves such a method. Though education does attempt to influence behavior, it does so by offering information in all its complexity, leaving it up to the individual to decide how to act on that information. Sadly, however, propaganda is much more successful than education.

propaganda → influence by slogan → /education

Selena claims to have psychic powers. So if we find out whether Selena's claim is true, we will thereby determine whether it is possible to have psychic powers.

WHATS THE MISSING LINK?

LINK: If it is possible to have psychic powers, then Selena has them.

Authors conclusion means: If we find out that Selena does have psychic powers, then we will determine that it’s possible to have psychic powers. And, if we find out that Selena does NOT have psychic powers, then we will determine that it’s NOT possible to have psychic powers.

If Selena has psychic powers, then it’s inherently true that having psychic powers is possible.

But if Selena doesn’t have psychic powers, that doesn’t necessarily prove that it’s impossible to have psychic powers. After all, what if someone else besides Selena could have psychic powers.

So to make the argument valid, we want to establish that if Selena doesn’t have psychic powers, it’s impossible to have psychic powers. In other words, we want to know that nobody else can have psychic powers if Selena doesn’t have them.

To classify a work of art as truly great, it is necessary that the work have both originality and far-reaching influence upon the artistic community….The principle above, if valid, most strongly supports which one of the following arguments?

What kind of conclusions can you draw from this kind of conditional?

The correct AC is one that fulfills the contrapositive

Conditional is:

• Truly Great → Originality AND Influence

• /Originality OR /Influence → /Truly Great

In a case like this, we’re told what’s NECESSARY for an artwork to be truly great. So we can conclude that an artwork is NOT truly great. But we can’t use the principle to conclude that an artwork IS truly great

Attacks on an opponent's character should be avoided in political debates. Such attacks do not confront the opponent's argument; instead they attempt to cast doubt on the opponent's moral right to be in the debate at all….Which one of the following principles, if valid, most helps to justify the reasoning above?

What form are you looking for in correct AC?

The correct AC is a conditional in which the conclusion is B—the NECESSARY condition

Question Stem:

• The one we have is… Attack Opponents Character → /Confront Argument

• The conclusion is “attacks on opponents character should be avoided”

So the conditional we’re need is… /Confront Argument → Should be Avoided

One answer choice was “Questions of character should be raised in political debate if they are relevant to the opponent's argument” This is wrong because Avoid would show up as the SUFFICIENT (in the contrapositive) and we need to be the NECESSARY condition to prove the argument

If understanding a word always involves knowing its dictionary definition, then understanding a word requires understanding the words that occur in that definition. But clearly there are people—for example, all babies—who do not know the dictionary definitions of some of the words they utter.

What conclusion can you draw from this?

xxx

Whenever she considers voting in an election to select one candidate for a position and there is at least one issue important to her, Kay uses the following principle in choosing which course of action to take: it is acceptable for me to vote for a candidate whose opinions differ from mine on at least one issue important to me whenever I disagree with each of the other candidates on even more such issues; it is otherwise unacceptable to vote for that candidate.

xxx - list of conditions approach

If Skiff's book is published this year, Professor Nguyen vows she will urge the dean to promote Skiff. Thus, if Skiff's book is as important and as well written as Skiff claims, he will be promoted, for Nguyen will certainly keep her promise, and the dean will surely promote Skiff if Nguyen recommends it.

This is an SA question and correct answer is: “Skiff's book will be published this year if it is as important as he claims it is”. WHY DOES THIS WORK?

We need a link thats going to link “Skiff's book is as important and as well written as Skiff claims” and getting published

You would think it would be… Imp and WW → published

It works because the phrase “Skiff’s books…” IS NOT A RULE, ITS APPLICATION. You need to supply the rule that fits and this rule fits. Its like if you said “if i go to the grocery store, i will get flowers”. Well if you go to the grocery store AND the gas station you will get flowers even though the gas station wasnt part of the rule

A first-term board member should not be on the finance committee unless he or she is an accountant or his or her membership on the committee is supported by all the members of the board.

WHATS THE CONDITIONAL YOU NEED TO CHECK AN APPLICATION?

Assuming first term board member… /accountant AND /supported → /finance committee

Archaeologists are currently analyzing plant remains found at a site that was last occupied more than 10,000 years ago. If the plants were cultivated, then the people who occupied the site discovered agriculture thousands of years before any other people are known to have done so. On the other hand, if the plants were wild—that is, uncultivated—then the people who occupied the site ate a wider variety of wild plants than did any other people at the time.

WHATS THE CONDITIONAL THREAD?

/wider variety of WP → cultivated → discovered ag

Sometimes one reads a poem and believes that the poem expresses contradictory ideas, even if it is a great poem. So it is wrong to think that the meaning of a poem is whatever the author intends to communicate to the reader by means of the poem. No one who is writing a great poem intends it to communicate contradictory ideas.

XXX

Every delegate to the convention is a party member. Some delegates to the convention are government officials, and each government official who is at the convention is a speaker at the convention, as well.

What inferences can you draw?

speaker ← gov ←(s)→ delegate → party member

INFERENCES:

• speaker ←(s)→ delegate

• gov ←(s)→ party member

Only when we know a lot about the events that led to an action are we justified in praising or blaming a person for that action—as we sometimes are. We must therefore reject Tolstoy’s rash claim that if we knew a lot about the events leading up to any action, we would cease to regard that action as freely performed.

xxxx

All social systems are based upon a division of economic roles. The values of a social system are embodied in the prestige accorded persons who fill various economic roles. It is therefore unsurprising that, for any social system, the introduction of labor-saving technology that makes certain economic roles obsolete will tend to undermine the values in that social system.

WHAT MUST BE TRUE?

LOOK AT LAST SENTENCE…

• If labor-saving technology is introduced, social systems will be undermined.

• So taking the CONTRA—if social systems cannot be undermined (cannot be changed), labor-saving tech cannot be introduced

A ← B → /C

A (s)→ /C

A → B → /C

A → /C

A ← /B ← C

/A ← C

A ←(m) B → /C

A (s)→ /C

A (m)→ B → /C

A (m)→ /C

A → /B ←(m) C

/A ←(m) C

A → /B → C

/A (s)→ C

A → /B (m)→ C

/A (s)→ C

A ← B → C

A (s)→ C

A ← B (m)→ C

A (s)→ C

A ←(m) B (m)→ C

A (s)→ C

A (s)→ B (s)→ C

NO INFERENCE

A (s)→ B (m)→ C

NO INFERENCE

A (m)→ B (m)→ C

NO INFERENCE

A (m)→ B ←(m) C

NO INFERENCE

Every student who walks to school goes home for lunch. It follows that some students who have part-time jobs do not walk to school. MISSING LINK?

conclusion is /walk so we know that we have to take contra of premise: /home lunch → /walk

the premise of the conclusion is “ptj (s) →”

so chain must be… ptj (s) → /home lunch → /walk

MISSING LINK: ptj (s) → /home lunch

A ←(s)→ B → C

A ←(s)→ C

A (s) → B ← C

NO INFERENCE

A ← B ←(s)→ C

A ←(s)→ C

A ← B (s) → C

NO INFERENCE

Humorous television advertisements are the only effective ones. For if something is humorous it will not only attract people's attention, it will hold their attention long enough for a message to be conveyed. And, obviously, for an advertisement to be effective it must convey its message.

WHAT IS THE FLAW?

It treats humor as a NECESSARY condition for conveying a message when it isnt. The flawed argument is…

effective → convey message

convey message → humor

CONCLUSION: effective → humor

Each new car in the lot at Rollway Motors costs more than $18,000. Any car in their lot that is ten or more years old costs less than $5,000. Thus, if a car in Rollway's lot costs between $5,000 and $18,000, it is a used car that is less than ten years old.

WHY IS THE CONCLUSION VALID?

It is valid under the contrapositive of both statements. If it doesnt cost more than 18k, its not new. If it doesnt cost less than 5k, its less than 10 years old

It is an absurd idea that whatever artistic endeavor the government refuses to support it does not allow, as one can see by rephrasing the statement to read: No one is allowed to create art without a government subsidy.

WHAT IS THE PATTERN OF REASONING?

That's identical to the original claim. So the rephrasing is just a logically equivalent way of stating the same conditional. The author hasn't changed the logic at all. She's just reworded it.

Congenial guests and a plentiful supply of good things to eat and drink will ensure a successful dinner party. Since Sylvia has prepared more than enough to eat and drink and her guests are all congenial people, her dinner party is certain to be a success.

WHAT IS THE FLAW?

The argument gives a conditional rule with a two-part sufficient condition AND DOESNT MEET BOTH SCs. While we know for sure that Sylvia has congenial guests, we only know that she has plentiful food and drink — we don't know that she has plentiful good food and drink

Any good garden compost may appropriately be used for soil drainage and fertility. The best compost is 40 to 60 percent organic matter and is dark brown in color. However, compost that emits a strong ammonia smell should not be used for drainage and fertility, for that smell means that the organic matter has not sufficiently decomposed.

WHAT IS THE CHAIN?

good compost (including best) → S and F → /Ammonia

Any writer whose purpose is personal expression sometimes uses words ambiguously. Every poet's purpose is personal expression. Thus no poetry reader's enjoyment depends on attaining a precise understanding of what the poet means.

WHAT IS THE MISSING LINK?

No writer who ever uses words ambiguously has any reader whose enjoyment depends on attaining a precise understanding of what the writer means.

Many nurseries sell fruit trees that they label "miniature." Not all nurseries, however, use this term in the same way. While some nurseries label any nectarine trees of the Stark Sweet Melody variety as "miniature," for example, others do not. One thing that is clear is that if a variety of fruit tree is not suitable for growing in a tub or a pot, no tree of that variety can be correctly labeled "miniature."

Which of the following can be properly inferred…

A) Some of the nurseries have correctly labeled nectarine trees of the Stark Sweet Melody variety only if the variety is unsuitable for growing in a tub or a pot.

B) Unless the Stark Sweet Melody variety of nectarine tree is suitable for growing in a tub or a pot, some nurseries mislabel this variety of tree.

Has to be B. Lets model these out

A) correct ←(s)→ /suitable for large pots

B) correct ←(s)→ suitable for large pots

B is the conditional statement given in the stimulus. It has to be this one because SOME CONDITIONS HAVE NO CONTRAPOSITIVE

Most people who are skilled banjo players are also skilled guitar players. But most people who are skilled guitar players are not skilled banjo players.

WHAT MUST BE TRUE?

B (m)→ G BUT G (m)→ /B

It must be true that there are more skilled guitar players than banjo players. Think about this as the circle diargrams that 7sage uses. G is the NC so the G circle is larger. Most B are G but that doesnt mean most G are B.

Phonemic awareness, or the knowledge that spoken language can be broken into component sounds, is essential for learning to read an alphabetic language. But one also needs to learn how sounds are symbolically represented by means of letters; otherwise, phonemic awareness will not translate into the ability to read an alphabetic language. Yet many children who are taught by the whole-language method, which emphasizes the ways words sound, learn to read alphabetic languages.

WHICH OF THE FOLLOWING THINGS CAN BE PROPERLY INFERRED?

(A) Some children who are taught by the whole-language method are not prevented from learning how sounds are represented by means of letters

(B) The whole-language method succeeds in teaching many children how to represent sounds symbolically by means of letters.

Chain is WLM → learn to read → phonemic awareness and sound symbolism

Has to be A because we dont know that WLM teaches them sound symbolism. We just know that some of them learn it somehow and therefore some arent prevented from learning it