Similar question to practice: 149-1-18.

It is a MBT question, but it requires similar reasoning to get to the correct AC. The stimulus provides two conditional statements that aren't explicitly related, but you can draw a reasonable inference about their relationship, which then allows you to draw the contrapositive and infer a relationship that MBT.

Add to this thread if you find examples of other questions that use a similar reasoning!

Hi! I was a bit confused at first too. I have a short and long response; hopefully both are helpful.

Q2 and Q4 are similar in that they both make a "some" statement. The difference between Q2 and Q4 is that they make a different claim about the relationship between the two ideas in the original statement. Q2 denies that there is a "some" relationship, while Q4 claims that there is a "some" relationship. It is important to note when a statement contains "not", because "not" represents "/" and that "/" should be included when you map out the logical notation.

What helped me is recognizing:

(1) the 2-step process for negating "some" statements vs. the final negated statement;

(2) the meaning of the original vs. negated statements; and

(3) the meaning of contrapositive statements & how that relates to the relationship between "no" and "all."

Regarding (1):

"Some" statement: A ←s→ B

There are 2 steps in the process for negating "Some" statements:

Step 1: swap the "←s→ " and turn it into a "→"; and

Step 2: slap a negation "/" on the necessary condition.

For question 2, the original "Some" statement is:

Some alphabets are not phonetic. A ←s→ /P

Step 1 (swap): A → /P

Step 2 (slap): A → P

the necessary condition in the original statement already had a negative idea indicated by the "/" aka the "not" in "not phonetic," so when we negate the relationship, by slapping on a "/", the two "/" cancel out.

Therefore, the final negated statement is: A → P. All alphabets are phonetic. (A → P)

The negated statement in Q4 matches the form A → /B from the negating "some" video because the set up in this question is the same from the video. The Q2 set up is different because the original statement contains a "not." To arrive at the correct negated statement, you must recognize the meaning of the original relationship (is it a claim of declaring that a relationship exists, or a claim denying the relationship?), map the relationship correctly, and apply the two-steps.

Regarding (2):

How could the negation contain an "all" statement, if we were taught that the negation of some is "none"? Well, we have to think beyond just the logic notation, and think about the literal meaning of the original statement and the negated statement and what they are claiming about the relationship between the two ideas "alphabet" and "phonetic." The original statement is a claim that denies a relationship between alphabets & being phonetic. The negated statement denies that denied relationship; in other words, the negated statement effectively says, "hey, there is a relationship between alphabets & being phonetic!"

Regarding (3):

To negate a "some" statement, you can say:

"All A are not B" A → /B or

"No A are B" B → /A

These are logically equivalent statements, aka contrapositives.

Based on the original statement, when we apply the 2 steps to negate "some" statements, we arrive at the negated statement: A → P.

The contrapositive of this is: / P → / A.

The tricky part in Q2 is recognizing that the original statement is like a negated statement, because it is a claim that is denying a relationship by using "not". So we have to negate that negated relationship. However, we will typically see, like in Q4, that we will be given a claim that a relationship exists (like a correlation) and we have to negate that relationship, so the negated claim will match what you anticipated like in Q4.

Hi! I don't know about all the inferences you can make about B & C from those statements, but your question reminded me of these 2 parallel flaw questions:

117-4-19

138-2-25

Does anyone know of any other questions that use logic similar to this question? I'd find it helpful if there are any other examples I can use to practice this MBT question re. percentages & averages.

Another MSS question relating to correlation implying causation: 141-4-8.

I chose A over E because I thought that A was describing the flaw in the reasoning---how the premises failed to support the conclusion; so the emphasis was on the relationship between P & C. vs. E was an attempt to propose an alternative explanation (therefore attacking the conclusion), but ultimately is still consistent with the conclusion being true.

To distinguish between ACs, I ask, how does this AC relate to the premises---specifically regarding how the premises do not guarantee support for the conclusion.

J.Y. mentioned that there is a question that uses similar subject matter & logic in another PT. Does anyone know which PT & question that is?

One takeaway I had from this passage is paying attention to when the author describes necessary conditions and necessary assumptions. Even just noting a "NC" in my LRS made a huge difference for me to refer back to it when answering questions.

Recognizing the necessary conditions/necessary assumptions in this passage can help answer some questions, especially #17 and #21.

(1) Describes a necessary condition for TE.

"Theoretical equipoise exists only when the overall evidence for each of the two treatment regimens is judged by each clinical researcher to be exactly balanced---an ideal hardly attainable in practice." Meaning, a requirement for TE is that clinical researchers judges both treatments as balanced.

TE → balanced judgment

(2) Describes a necessary assumption for CE & the author's argument. (I anticipated this point might come up in a Weaken question & it did in #21!). I got 4/8 questions wrong on this passage (!!), but surprisingly got #21 right & within 10 seconds of the target time.

"The very absence of consensus within the expert clinical community is what makes clinical equipoise possible." No clear logical indicators here, but the simple interpretation of this sentence is describing a requirement that the author depends for their argument. Meaning, CE requires absence of consensus.

#17

(D): first half of this AC: describes that the necessary condition failed, so the argument is destroyed, or, using the phrase from the question stem, TE is "jeopardized."

/balanced judgment → /TE.

second half: the necessary condition is intact, so the argument is not impacted by this statement; CE still stands.

regarding trap AC (A): you can eliminate this AC because the scenario described does not match the explicit conditions laid out in the passage. This AC uses a lot of words, but it's a distraction. (A) doesn't deliver clear consequences based on the scenario from the passage. It does not deliver consequences that the argument cares about.

#21

(A) This negates the author's necessary assumption, effectively weakening the author's argument. Necessary assumption negated: "It is not the case that comparative clinical trials require the absence of consensus." This AC means that comparative clinical trials do not require the absence of consensus; instead, comparative clinical trials are conducted for the purpose of confirming consensus by proving that the consensus is correct.

Although this AC does not explicitly mention clinical equipoise, the consequence of this AC relates to the author's argument, given the inferences that we can draw (from paras 3 & 4) about the relationship between comparative clinical trials and clinical equipoise.

Thoughts? Have you observed this or used this strategy for other passages? If this is a pattern and solid approach to RC passages, I think it would be interesting to see a compilation and application of this approach in a live class.

Hi! Would it be fair to say that we could interpret the stimulus by using the method of "kick it up into the domain" for artists? So that the sufficient conditions are skill + creativity.

I see what you're saying! I initially had that same reaction.

I think D doesn't necessarily provide its own evidence out left field, and actually does strengthen the connection to the premises because D makes explicit the connection between feeling emotion and the sound of singing, which are the two main ideas from the scientists' hypothesis. So it's actually a bullseye AC, but its relevance is a bit hidden because instead of using the same language from the stimulus: "emotion noticeably affects the sound of singing", this AC is more specific and refers to "emotions [that] affect the vocal cords and lungs." The details seem random or extra, but they strongly relate to the phenomenon-hypothesis from the stimulus.

Below is a list of Strengthen questions in which the correct AC is one that strengthens the argument by describing a causal mechanism.

This could be an AC that provides a (1) detailed causal chain or (2) provides an additional causal mechanism in which the conclusion can be reached.

134-3-17

141-4-20

147-1-10

147-4-14

If you come across any others, add them to this comment thread! :)

I agree that a separate letter from each of them may be redundant and overall less effective for your application. Although generally this may not be recommended/is uncommon, I think it makes sense given your specific context for them to write a jointly signed letter! Since you work very closely with them, at a small firm, and since they are partners at the firm & partners in their relationship! Just note that/as an FYI, when you submit a request on LSAC, you will only fill out the name & contact information for one of them, not both. Only one of your recommenders will receive an email from LSAC inviting them to submit the recommendation. However, if you want to clearly communicate that it is a joint letter, then the actual letter can be signed by both of them and contain both of their contact information.

Although you've graduated in 2021, law schools strongly recommend letters of recommendation from your professors. I recommend reaching out to your professors to catch up (even if it's over the phone or Zoom), updating them about your law school plans, and asking if they'd be able to write you a strong recommendation. You can offer to provide them a "tip sheet" of information that you think would be helpful for them to reference as they prepare their letter---sort of like refreshing their memory and encouraging them to highlight specific points. Admissions officers even recommend that you do this for your recommenders. I think your professors would be more willing to write the letter too.

Here's a tip sheet I found online: https://admissions.law.yale.edu/apply/LOR_Tip_Sheet.pdf

I'm sure there are others too; I just found this one very helpful! Wishing you the very best!

Hi! What do you mean by bottom up vs. bottom down support? Does bottom up support refer to strengthen questions and bottom down support refer to MSS?

I know this is 3 years later, but for anyone else that comes across this and has the same question, I think 153-2-17 is an example in which the correct AC describes a qualifying statement.

I've just started drilling AP questions and I've noticed a couple of AP questions that have tempting trap ACs that try to bait us to fall for this same reasoning flaw of "lack of support vs. false conclusion."

The stimulus structure is as follows: (1) other people's argument/hypothesis is stated, & (2) the author points out a potential flaw in their argument by disagreeing with and/or questioning the support structure (premise) of other people's argument/hypothesis.

Here are some examples of AP questions that contain the stimulus structure I described above & have a trap AC that is a "lack of support vs. false conclusion" flaw:

131-2-7

147-1-22

My takeaway from these types of questions is recognizing that:

(1) the author is (usually) not providing an alternative hypothesis/explanation/conclusion,

(2) the author is not completely disagreeing with other people's argument/hypothesis/conclusion (in other words the author is not saying other people's conclusion is false or wrong),

and (3) the author is actually just saying something softer, along the lines of: "hey, your argument isn't airtight & lacks support given [X reason/flaw]".

The TRAP ACs bait you to assume:

(1) the author provided an alternative hypothesis and/or

(2) the author is arguing that other people's argument is false.

To avoid selecting these trap ACs, I ask myself, did the author explicitly (1) provide an alternative hypo or (2) say that other people's argument is false? If not, it is most likely the case that the author's purpose of writing the stimulus and point of emphasis/takeaway for us readers is to highlight a flaw in other people's argument---which is all about how the conclusion does not follow from the premise(s).

Hi! I had the same question as you. Here's what I came up with & I'm curious to hear your thoughts!:

The stimulus does not explicitly say that a singular study was performed (although it is easy for us to assume this). In other questions, we are given explicit phrases that make it clear the author is talking about a singular study or experiment (e.g., "In a study of [X]..." or "One study showed that..."). From this, we have more reason to be hesitant of generalization claims.

The way this stimulus is written---with points of comparison/clear parameters---the stimulus makes me think of experiments (which may be what the LSAT writers intended). Maybe you relate to this, too; I thought to myself, "okay this is like an experiment, there is a clear control variable, clear variable we are measuring, etc..."

However, by focusing on the specific words on the page, we can notice that the stimulus is written very generally (e.g., “Given any [...], such a program will [...]”). So, what the stimulus is actually saying is a very general claim (which the correct AC paraphrases).

In general, I think that when we see "in general" (or similar language) in ACs, we should be mindful of over-generalizations. Especially because oftentimes the stimulus contains explicit language that an experiment/study was conducted that led to X results. So it is reasonable to ask, like you did, "How can we say that the result of only one control experiment most strongly supports a general claim?" However, in this specific question, the stimulus is written generally. Another 7Sager wrote this comment that I found helpful: “in general” can be interpreted as a subtle paraphrase on when the chess playing programs have a better chance of winning.

Is this question an example of the following?:

Correlation in the stimulus, which is at least some evidence of causation.

(But does NOT PROVE/GUARANTEE causation.) Sometimes there is a stimulus that requires us to recognize that correlation is evidence of cause. And then depending on whether you’re able to control for other factors, it becomes more likely that correlation really is strong evidence of cause.

Curious to hear what y'all think!

The last answer choice (F) that could be an answer choice if LSAC wanted to make this question more difficult, what valid argument form is J.Y. referring to? Is it related to valid argument form #6 (Two Split Mosts)?

Since we know that:

all implies most, and most implies some;

and two split mosts implies some.

So, we can conclude that two split alls also implies some.

Is this correct?

Hi! Would this flaw be considered a hasty generalization? Also, I'm wondering would this flaw be considered an example of the invalid argument form: "All Before Some"? https://7sage.com/lessons/foundations/formal-logic-flaws/all-before-some

I also wondered this! But ultimately I think that the answer to the question you raised doesn't matter at all given the task at hand. Based on the stimulus, we have no reason to believe that all the editions afterwards would be hardbacks vs. they wouldn't be hardbacks. So we'd have to make an unwarranted assumption either way to answer your question. But this "what if" question is tangential to the core question/assumption at hand, which is what (C) addresses. We're not trying to 100% destroy the author's argument, which your question aims to do. Rather, we want to weaken the argument by at least 1%. So it's good reminder to not give ourselves a task that goes beyond what the question stem gave us, because then we may rule out the correct AC and miss the bar completely.

Although you posted this 2 years ago & you might not be studying for the LSAT anymore, I hope my comment helps anyone else wondering this!

Hi! I also picked E. Here's why I think E is wrong.

1. It provides new data/information that is consistent with the hypothesis being either true or false; therefore there is no targeted impact on the argument.

2. It is an assumption bait. It provides incomplete information, and hopes that we'll fill in the gaps with unreasonable assumptions.

3. It is an attractive trap because it appears to provide an alternative hypothesis, which is what we're anticipating. But, it is incorrect because given the simple meaning/interpretation of this AC; its position/impact on the argument is unclear, and this leaves room for trap assumptions.

1. The new information here is the "new thermal-insulating technology."

2. What do we know about this new tech? It was "widely applied in house building" "soon after WWII." That's all we know. This AC raises more questions than provides explicit answers. It wouldn't meet the bar of answering a MSS question (think: "I was born yesterday, based on the text only, what inferences can I make?").

3. This is baiting us to assume that this new tech has a particular relationship with architecture. But we have no reason to assume any relationship. It is unreasonable to assume that E provides an alternative cause for the architectural change. Why is this unreasonable? Because, we don't have details about the application that we'd need to make inferences that would strictly weaken the author's hypothesis. Was this application successful? Was this technology applied to (X) houses with high ceilings and thick walls or to (Y) houses with low ceilings and thin walls? We don't know. It would be unreasonable to assume (X) over (Y) or vice-versa, since we have no insight into the application process. Let's say we assume that it was applied to both (X) & (Y). How would this affect the argument? Unclear. It's possible that the new tech made A/C work better or work worse. What if this new technology was more expensive, and it would be more cost-effective to have houses with A/C, so people prioritized houses with A/C? So many questions and possible directions this AC can lead us to!

One way that has helped me in checking myself to see if I'm making a biased, unwarranted assumption is by thinking about Evaluate questions. For Evaluate questions, we're looking for an AC that could either weaken or strengthen the argument, depending on how we interpret it. If we pose it to one extreme, it will weaken, if we interpret it to the other extreme, it'll do the opposite. So with (E), you can think of it as like an Evaluate AC. Depending on how you interpret it, it will weaken or strengthen. But (C) is sufficient on its own. No matter how you interpret it, (C) weakens the argument. (C) doesn't need any additional assumptions to make it better. We don't provide an argument for the correct AC, the correct AC presents itself to us. (E) relies on us making a case for it; (C) doesn't.

Ultimately, the plain meaning of (E) raises more questions than answers, appealing to our biases, and baiting us to make assumptions so that this AC fits our anticipation of being an alternative hypothesis. But the core of this AC has no explicit weakening impact on the argument, so it cannot be the correct AC.

Curious to hear your (or anyone else's) thoughts!

I couldn't identify the flaw type beforehand, but my pre-phrase was: there can be multiple necessary conditions to achieve this effect, the conclusion assumes that there is only one way. Vigorous exercise is just ONE of the ways one can lower one's chances of developing certain cardio-respiratory illnesses. So, the older studies proposing an alternative method (nonstrenuous walking) to achieve the same health benefits can also be valid; just because it's different doesn't mean that it is definitely wrong.

Thoughts?

Hi, I understand why C) is correct. I don't fully understand why A) is incorrect. Could someone help me understand? I thought A) could potentially weaken the argument because this would mean that the study wasn't done properly, and if it's a flawed study, we can't make such a strong conclusion.

My takeaways from this question:

Understand what claims are made in the stimulus that are used as evidence for the argument. Recognize that these claims may make an underlying assumption, find it and make it explicit in your mind. Given the reasoning made in the stimulus, approach the ACs with a targeted mission to make that specific assumption more concrete/close the gap/answer any questions/potential rebuttals. The correct AC deepens/confirms/extends that hidden assumption with related, new evidence that makes me more likely to believe in the reasoning from the stimulus (i.e., more likely to understand/see how the premises support the conclusion).

Here, the stimulus' conclusion is that: hey we don't strongly believe that this guy was a bad guy. The reasoning? The stimulus makes claims about the existing evidence---(1) the quantity and (2) the quality.

(1) Quantity: there isn't much documentation. Underlying assumption: when there's little evidence, we're less likely to believe (or strongly believe) in a conclusion (here the modern historians are challenging the traditional view). Ok, simple enough reasoning. I don't see any gaps with this or rebuttals I'd need to address, so I'm not going to focus on ACs that talk about the amount of the evidence.

(2) Quality: out of what little documentation we do have, these documents were written by his enemies. Underlying assumption: how can we trust these documents? The enemies were probably biased and the documentation is not true, or at least suspicious/questionable. Ok, this reasoning regarding the quality of the nature of the evidence has room to be strengthened; it isn't as straightforward/tight reasoning compared to the first premise. Can we deepen the suspicion about the quality of the evidence? Can we find an AC that---if true---would make us at least 1% more likely for us to want to challenge the traditional view?

The correct AC subtly strengthens the argument. Here, POE is the best way to arrive at the correct AC. This correct AC both (1) relates to the underlying assumption made in the stimulus (his enemies are biased and we can't fully trust the quality of the documentation), and (2) provides related, yet different evidence that deepens this reasoning, therefore making us more likely to believe in the conclusion (we have doubts that this guy was a bad guy; we can't be so confident in saying he was a tyrant). This correct AC gives us another reason to doubt the traditional view. The correct AC makes the enemies "evidence" even more suspicious, and that's all that we really have to do here--just make the argument 1% stronger.

I'm struggling to confidently categorize this correct AC, but I'm thinking that this AC strengthens the argument by providing circumstantial/corroborating evidence?

Thoughts? I appreciate any feedback/commentary!

Update: question 9 from pt 149 section 1 is a PSAr question in which the correct AC is the contrapositive!