@lsattaker264 This was my hang-up too!

(D) can be thought of as strengthening the argument by dispelling a potential competing hypothesis (that tourists were staying in the city longer for their visits and thus spending more on hotels and food, without increasing the amount of money spent on passes).

For (E) to actually weaken, we'd need to assume that the painting of the historic battle accurately represents the figures involved in the battle (and does not include any additional figures). That is a major and unwarranted assumption, especially considering that (D) marginally weakens without needing any such assumption.

@Xexne198 That's fair. I think the main issue with (B) is that the two possible outcomes -- "succeeds" and "fails" in the stimulus, which are opposites of one another -- aren't opposites in this answer choice. (D), on the other hand, maintains this "pair of opposite outcomes" relationship.

Using the method of reasoning in the stimulus, we could similarly argue that, because floods have always been preceded by rain, the fact that it's raining outside means it's about to flood. But that would be unreasonable! Consider that floods only follow a tiny portion of rain episodes.

The abstracted flaw is: X has always been preceded by Y. Therefore, the presence of Y means that X is impending.

(E) matches that abstracted flaw.

If it helps, you can also think about this as a quasi-sufficiency/necessity mistake: in our domain of discussion, earthquake --> tremors came before. Tremors came. Therefore, earthquake is coming.

@mh212529 The question stem says "to the policy...not advocated by the author of passage B?" The way this question is phrased does not require outright rejection by passage B. Rather, the correct answer choice simply needs to express a policy that was advocated by passage A and not advocated for by B. "Not advocated for by B" can mean an outright rejection of the policy, a hint at a rejection of the policy, or no mention of the policy -- anything so long as it is not advocacy.

@nicoleegatto791 I agree. I don't love how the written explanation for (C) says that "The analogy isn't between the info processed by a brain and the info transmitted by the Internet," since there is in fact an analogy between those two means of transmitting information as stated in the first sentence of the stimulus. Then there's a second analogy about the brain and the Internet. It's just that it's this second analogy that is the dubious one, not the first, hence why (C) is wrong.

@Zach Sadorra I think I see what you're getting at here. Here's how I'm thinking about this. I think JY's diagram in the video is helpful, parsing out "things we (the readers) know" and "things this group believes."

For (A), "Many people who criticize etiquette have contradictory views of etiquette" is unsupported. All we know about this "many people" group is that: 1) they believe that etiquette has no beneficial effects for society and 2) they believe that kindness and social harmony are good. Do those two beliefs alone contradict one another? No. Perhaps this group simply doesn't believe that etiquette promotes social harmony, even though we know -- as a factual matter from the factual premise found in the first sentence of the stimulus -- that etiquette does in reality promote social harmony. But again, we don't know whether this group of people believes this fact. Without knowing whether or not they believe this fact we are given, we have no evidence of internally contradictory beliefs about etiquette.

Now for (C), "Many people who criticize etiquette are mistaken about its beneficial effects for society." The operative word here is "mistaken." Notice that (C) doesn't specify exactly how this group is mistaken. There are a few ways. Consider this one: this group of "many people" believes that etiquette has no benefit for society. We are told that, in reality, etiquette promotes social harmony. Why is that relevant? Well, this group believes that social harmony is good. So this group is mistaken in their assessment of etiquette: if this group of people adopted belief in the fact presented about etiquette -- that it promotes social harmony -- then they would be forced to abandon their belief that etiquette has no societal benefit, or vice versa, to prevent internal contradictions. But as it stands, this group has a belief about etiquette that is mistaken relative to what we are told about reality: based on their belief that social harmony is good, they are mistaken that etiquette produces no social goods. Why? Because we are told -- as a factual, not belief-based, matter -- that etiquette promotes social harmony.

So the sense of "mistaken" here is an incongruence between reality (etiquette promotes social harmony) and belief (etiquette produces no benefit for society, even though this group believes social harmony is a benefit for society).

(A) is dealing with internal incongruence ("contradictory"), whereas (C) is dealing with the incongruence between belief and reality.

I struggled with this question but hope my long-winded answer helps at least a little bit here.

To add on to why (C) is wrong: (C) might very well be useful in explaining this trend if we were told whether Jones's theory is a line of research that scientists in the field generally accept. That would possibly help explain why more scientists are doing research along the lines of Jones's work, and if the scholarly consensus is that Jones is correct, and she is in fact correct, then it is reasonable that these additional data points (corrections) are in line with Jones's thinking. But we aren't told whether Jones's theory is regarded as such.

Combine that with the issue the written explanation points out and I think you get a strong reason for rejecting (C).

@lilikim2002275 This was my concern too. I think it comes down to having to make the assumption that, by fulfilling a NC, you increase the likelihood of obtaining the SC in some cases. While not always true, it's a smaller assumption than conflating sufficiency and necessity.

The written explanation for (D) currently says, "The nerve sheath will not disintegrate if it contains living nerve tissue." That explanation is wrong because it confuses sufficiency and necessity in translating the "unless" relationship. I messaged 7Sage and they said the content team is going to update the explanation accordingly.

@rahenderson407 I see what you're saying. I think it comes down to the fact that (B) deals with slowing or stopping disintegration after the disintegration has already begun, whereas the stimulus tells us about when disintegration might begin. This difference in the domains being discussed in the stimulus and in (B) makes (B) unsupported.

(D), on the other hand, requires the assumption that the fulfillment of a NC increases the likelihood of obtaining the SC in some cases. While this isn't airtight -- we can think of situations in which fulfilling a NC does not increase the odds we obtain the SC -- it's a reasonably supported assumption in the context of probabilistic reasoning on a diverse data set.

Take that all with a grain of salt, but that's the conclusion I've come to with this question.

@Ai Xing I agree. I submitted a note on that through the "ask a tutor" button, so hopefully they'll fix the written explanation for (B).

@lsatscorer1239 As Mike Kim mentions in LSAT Trainer, there will only be one AC that weakens for weaken questions and only one AC that strengthens for strengthen questions, meaning you don't have to worry about assigning how many "utils of weakening" different ACs do and then choose the one that does the most weakening. As Kim points out, requiring this kind of comparison would lead to ambiguous questions, since it's very difficult to quantify to what degree different ACs weaken an argument...a recipe for disaster and bickering on a standardized exam like the LSAT. But it does not require any arbitrary quantification to determine whether an AC does or does not weaken an argument.

That said, for some high-level weakening questions, particularly ones that might have multiple ACs that could conceivably weaken the argument if you provide a set of assumptions with the AC, you will need to choose the AC that results in making the fewest significant assumptions possible. But even then, the question I still ask myself is "Which one of these ACs weakens the argument/which 4 do not weaken the argument?"

@Intersection The thrust of the scientist's argument is that the two premises (no active volcanoes identified and cyclical atmospheric composition) are sufficient for us not to accept the conclusion that volcanic activity caused the spike on Venus. By suggesting that Venus's conditions make it unlikely that an instrument would detect volcanoes directly, we are pointing to the possibility that there are in fact active volcanoes on Venus, just ones that haven't been detected directly.

Even with that being said, I'm sympathetic to your broader critique of this question. In reality, the scientist is simply saying that we shouldn't accept the grandiose conclusion that volcanic activity caused this spike on Venus. I'm inclined to think the scientist could still accommodate (A) to his argument, saying that "Sure, I grant that we don't have instruments that are likely to detect a volcanic eruption directly, leaving open the possibility that there are active volcanoes that we simply haven't detected. But my point is more modest: there is sufficient reason for us to doubt the conclusion that active volcanoes caused this spike, and the mere possibility of the existence of an undetected active volcano is not sufficient reason to believe that there is in fact an active volcano and that that active volcano was the cause of the spike." At least if I were the scientist, that's how I'd response to (A), the alleged weakener.

I think this question begs the question of what we actually mean when we say that an AC "weakens" an argument. If I'm the scientist and someone expresses (A) to me, I can still articulate how my conclusion can be legitimate even if (A) is true...But the truth of (A) nonetheless makes my first premise (that no active volcanoes have been identified on Venus) less powerful in triggering my conclusion than it otherwise would have been. I essentially then have to show that even with my weakened premise, my conclusion -- that there is not sufficient reason to conclude that volcanoes were the culprit -- has legs. So at the end of the day, I think it is for that reason -- that (A) makes the force with which that premise supports my conclusion less significant -- that makes (A) a legitimate weakener.

Sorry for the wordiness -- mostly wrote this as a way of externally processing this question. I think this stimulus is more complex than JY gives it credit for in the video.

Also, in a weird way, I think we can almost use an NA-esque approach to this question to see why (A) is a weakener. For the premise that "No active volcanoes have been identified on Venus" to support the conclusion that we shouldn't accept the claim in question, what needs to be true? Well, there needs to be some connection between what we detect and what's actually there, a sort of necessary assumption! By that logic, a way of weakening this line of reasoning is by suggesting that the necessary assumption does -- or might not -- obtain. What does (A) do? Suggests that the necessary assumption -- that there is some connection between detection and reality -- might not be true, by suggesting that the instruments we have can't detect things directly that might actually be there! I know that's kind of a weird mash-up way of thinking about this weakening question, and one I haven't really used on other weakening questions before, but I think it does explain why (A) actually does function as a marginal weakener.

This question is basically getting at why it's important to have a control group when assessing whether some experimental condition causes a change.

Here, there are other potential reasons for why fewer pears were lost to insects with the use of the new pesticide compared to the previous years. Perhaps winters were colder, meaning there were fewer insects alive during the warmer months to eat the pears. By having the control group described in (C), we can more meaningfully deduce whether the change we noticed with the use of the new pesticide was actually do to the pesticide or some other confounding variable.

@lazar.steven-1-1 Don't forget that, for PSA questions, over-broad principles/PSAs are fine...they get us to our conclusion and then some. You're right that (B) is wrong here, but I just wanted to mention that because it seemed like you were suggesting that over-broad PSAs/principles shouldn't be selected in PSA questions, which isn't the case.

@batcam28 I'm also confused as to the difference JY draws between the interrelation among sets and the membership of an object to a set. To me, that distinction seems a bit arbitrary, since we can just as easily conceptualize objects as subsets. Would appreciate help if anyone's figured out a good way to think about this! #help

@KorynLaff bonus --> marketing is a correct translation for (C).

"X is never Y" translates to X --> Y.

This is an interesting PSA question in that the argument has two gaps, only one of which is addressed by the correct answer. Makes me feel like it would have been written better as a strengthen question, but of course, LSAC didn't ask me :) And that fact doesn't keep (E) from being the best answer here.

#feedback

I think the better explanation for why (B) is wrong is that (B) is way too grandiose and sweeping of a claim. This is only a single study! To then infer that, in general (notice that the (B) isn't restricted to bounds of the study the stimulus is describing, unlike some of the other ACs) guessing what came before is more accurate than guessing based on a perceived pattern is way too hasty of a generalization.

The actual theory for why (D) must be true is pretty abstract and more complex than I originally gave it credit for. JY does a good job explaining it via boundary cases in the video. But the reality is I think that method would take way too long during an actual exam. What probably works best here is using process of elimination to note the blatantly wrong aspects of A, B, C, and E, noting that D uses "some" (a favorite for MBT correct answers), that the situation describe in (D) seems very likely, without having to get into the nitty gritty of the math involved, then moving on. The confidence with which we can eliminate the other answer choices here makes it, at least in my view, unnecessary to fully dive into the math here during a timed exam.

Did anyone have a pre-phrase that worked for them before heading to the answer choices here? (C) makes sense but didn't pick up on anything in my pre-phrase. I spotted that the modern historians are assuming 1) that there is a connection between document volume/amount and cruelty and 2) that the fact that the histories we have today were written by Caligula's enemies makes those histories less likely to be accurate. Neither of those assumptions seems to be strengthened by (C).

Maybe it's that (C) makes the first prong of the modern historians' evidence -- the scarcity of documentation -- even stronger by suggesting that even the scarce evidence that survives shows similarities to earlier works?

@7Sage Tutor This is helpful, thanks -- I originally eliminated (B) on the grounds that it attacks a premise (and that my natural reflex is to not attack the premises themselves). But now I realize that is what this irregular Qstem was explicitly asking us to do! ("...most seriously calls into question evidence...")

"A few" should be treated as "some." So "A few A are B" becomes A <-s-> B.

7Sage's Core Curriculum is very mapping-heavy -- and if that works for you, then great! But I've found it helpful to practice internalizing the Lawgic rules so that I can reduce the amount of transitions I need to write out by hand during a test.

For example, take "unless": "I won't like you unless you are nice to me" becomes "If you aren't nice to me, I won't like you," or /nice --> /like.

Or "no": "No apples are oranges" becomes "If something is an apple, it's not an orange," or apple --> /orange.

While writing these out can be helpful, I find it more useful to practice translating in my head (when I'm walking to class, etc), especially regarding things I see around me. Doing so has helped me internalize the rules more than diagramming by hand has. But of course, it's important to write things out when you're first learning the rules.

You can do the same exercise for any conditional indicator, as well as for taking contrapositives.

What prep are you doing in between your PTs? A plateau like this could indicate that you might need to change what you are doing between your practice tests -- while BR-ing is great, I haven't found that it alone is sufficient for significant improvement. I've recently been taking more timed sections and then blind reviewing them and have found that helpful, as well as targeted timed and untimed drills (all with BR afterwards).

For RC, I've also been doing some passage-mapping drills using old passages that I've already taken, especially for ones where I missed questions.