GMAT Critical Reasoning #1 LIVE w/GMAT Ninja: Strengthen, Weaken, & Assumption Questions



hello everybody my name is Charles byblos I'm the GMAT Club verbal expert and a tutor at GMAT ninja calm today's lecture is admittedly a little bit of an experiment we're gonna be talking about strength and weaken and assumption questions on critical reasoning on the GMAT and yeah that's one of the topics almost everybody here has studied or you've certainly seen plenty of questions in those categories three quick disclaimers and the reason why I call it a little bit of an experiment first of all I haven't never actually delivered a non-interactive lecture on critical reasoning before so all of our lessons even when I used to teach in classrooms were always interactive always kind of working with what what my students were saying was giving them trouble so this is a little bit strange staring into a camera we're gonna do our very very best to incorporate your questions and feedback from that chat screen for those of you who are watching this live but please bear with us as we try to figure out kind of the right pacing it's gonna be a little odd for me to kind of lecture at this camera about critical reasoning of all things because the heart of critical reasoning when we teach it is we want to get inside your head figure out what it is this making you miss read or use some funny logic on clinical reasoning so I'll do my best to try to capture that with a little bit of your feedback from the chat screen and also just from going through these questions before we're students second thing for those of you who are not watching this live this is live no second takes no edits so please no judgments and third thing one thing I'm very very strongly recommend there's a link posted on the chat page right now to a GMAT Club thread we'd like you to do go over to that thread download the the word file that has the five questions will be going through today that way it's in front of you if you have access to her printer or if you want to pull it up on some other screen and that ways we're going through stuff and I'm using the board you'll be able to kind of look to the side and still have those questions in front of you so if you have a moment please go to your printer go to that link make sure you've got those questions in front of you it's gonna make your life quite a bit easier as we go through this today okay so what is this webinar really bad so what really I'm after today is this is kind of a general beginners guide to critical reasoning but through the lens of strength and weekend and assumption questions I think you could probably argue that strengthen and weaken questions in particular is some of the most kind of fundamental critical reasoning questions you'll see it's not that you're necessarily going to see a ton of them when we kind of talk about these different questions heads on the GMAT the reality is you actually don't seem that many questions percentage-wise that fit really neatly into these boxes which of the following would most strengthen the argument how often do you see that maybe 5 or 10% of the questions are strengthened or weakened in very straightforward language part of that is that there's plenty of other question types out there paradoxes discrepancies boldface questions but part of it is that the GMAT often gets really creative with the phrasing so instead of just saying which the phone would most most strengthen this conclusion or which the phone would most weaken the argument they find ways to kind of put a whole bunch extra words in there so in reality this isn't usually that straightforward that said sure logically strengthening weakening those are everyday words you know what those things mean so the logic of those questions isn't particularly difficult which kind of brings me to the main thrust of what we're trying to do today so if it's not really about logic what is it the logic isn't too tough even assumption questions not that tough really when you think about what exactly it means to have a necessary assumption to an argument but what it's really about is what are you miss reading so the thing we see over and over and over both on the GMAT thread do you might Club threads and from our own students why do people miss critical reasoning it's generally a mystery of some sort there's some little words somewhere some little thing or maybe a big thing that you've misinterpreted or misread or twisted into something else you've paraphrased some sentence and turn to something that it doesn't really exactly exactly mean you're not being literal enough so core technique on critical reasoning is about finding ways to be precise precise precise capture exactly exactly what the argument is trying to say so we're gonna talk about quite a bit here again through the lens of these three types of questions is how do you facilitate more precise reading more precise reasoning and again everybody here knows what it means to strengthen something the question is if you're missing these how do we get you to just be more systematic more precise in ways that are gonna help you get those questions right and not just strengthen and weaken an assumption questions but everything right on critical reasoning these are the core skills that are going to be 80% of the battle so we're gonna talk about sort of three different key tools on critical reasoning that are gonna apply to almost everything or absolutely everything first of all first thing we always want you to do in critical reasoning is to think structurally what do I mean by that the nice thing about strengthen weaken and assumption questions they always come with a conclusion they have to somewhere and we'll see a couple cases here where it's not necessarily exactly where you think it's gonna be but there's something that you're trying to strengthen or weaken or in the case of an assumption something you're trying to reinforce there's some punchline of that passage that's the most important thing figuring out what logic leads to what conclusion on these kinds of questions what a lot of people tend to do if they're first starting out is they kind of read these critical reasoning passages as back back back fact and maybe they read it really really slowly and methodically and they go fact fact fact there's no logic there necessarily have you really dialed into this thing right here is the thing the author most desperately wants me to understand to buy into to agree with so once I think structurally and as we go through these four or five questions today will model kind of how to do that a little bit second thing what I always want you to do after you've kind of said okay I think I found the conclusion of the passage I think I know what the reasoning is that's given to support that that conclusion what we always want you to do is ask yourself this question over and over is what I'm thinking is it my words or is it their words why one of the easiest things to do is to put words in the passages mouth just a little bit in real life when we read we paraphrase always or almost always so if you go read some report that somebody puts on your desk at work you're not reading it exactly exactly exactly for the pinpoint precision of every word the authors given you you're reading for kind of the main points or maybe the main conclusions or kind of the general idea or that boldface thing you're gonna need to talk about in that meeting the next day you're not really sitting there going wait a minute I'm gonna hang on every single word here and be really really anal about interpreting every little thing critical reasoning you have to do that it's an natural way to read if you let that conclusion turn into something slightly different the ballgames completely different one kind of really really silly simple example I've given on the GMAT Club forums before imagine these four conclusions X is the best solution to a problem X is the only solution to a problem X is a good solution to a problem X is a solution to a problem logically those four conclusions are totally different strengthening them or weakening them or finding a necessary assumption is completely different if you're trying to support the idea that something's the only solution versus the best solution versus just a solution if you miss read that one word best or only or good or hallucinate it when it's not there that's when you're in trouble you're gonna miss the question guaranteed that little bit of paraphrasing can be absolutely deadly now parallels here and I talked about modifiers quite a bit what I mean by that is those little words that are gonna tweak the scope strength magnitude of a statement especially those conclusions on these questions heads so only you're good or best in this case now notice there's really really strong parallels here and there's a lot of the folks that watch our live webinars a lot of you guys are really good at quant verb a little bit more of a struggle think about how you do quite a few missed that word X is an integer X is an non zero X is negative X is non-negative that one little word that that gives you some qualifiers some modifier of X you notice that every time hopefully same thing here this is where you see a lot of parallels across different question types so critical reasoning is this different thing from Kuantan actually no it's very very similar in one sense if you're not being strict strict literal precise about those little words here and there same thing on sentence Corrections same thing on critical reasoning the same thing on one that's where errors come from that are avoidable okay third thing don't fall in love what I mean by that is the easiest mistake to make on critical reasoning we're reading comprehension or sentence correction I see it every day people will say okay I've read the passage I've read the question yeah I don't like a B yep that's exactly what I was thinking B's great and then you don't really read C D any very carefully in the idea that maybe you're trying to save time or something horrible idea the way to always always think about verbal all three question types all the time I always want you to find four wrong answers not one right answer why is that so important when you think about the people writing these they're somebody's got this great idea for a hard question and great idea for her question what makes it hard got this great idea for this is gonna be the right answer that's not that tempting here's the wrong answer that's really really tempting this wrong answer that sounds great I'm gonna get the readers to anticipate some answer and I'm gonna change one word in it and they're gonna pick it and they're gonna be wrong that's so commonly what you see in the structure of these one really really tempting beautiful wrong answer choice it sounds just like the kind of thing you would anticipate is a good answer but it's not because a couple of words have been changed to make it not quite right instead of saying oh yeah bees great that's what I was thinking instead we always want to do okay fine I'm gonna keep beat and as we go through the questions say you'll see any modeling this yeah I don't know why I'd be is wrong I'm gonna keep it let's say I know exactly why C is wrong let's say I can't understand D to save my life I have no idea what it means this happens that who you are happens to me happens to everybody sometimes you read a sentence why it's hard it makes no sense but instead of saying well I like be better I'm gonna keep it for doubt be conservative let's say you know exactly why a is wrong now you're down to two and then maybe as you kind of reconnect to the passage and go back through these you recognize that word that you misread on B and you realize well wait a minute that can't be right it's I don't know it's a triple negative or something great now you're stuck with D hope you like it even if you don't understand it or don't understand how it connects the passage there's your right answer so I want you guys to be absolutely religious for wrong answers always on your verbal not just one right answer and that's a habit of mind that's really really important sometimes that process the elimination every test-prep person in the world talks about process of elimination but don't let it become something that's just yep I'm crossing stuff out make sure that you're certain that those four are wrong and you identify why they're wrong the fifth one is your right answer don't fall in love with the one that sounds good to you okay so that's kind of the big picture of how I want you to think about critical reasoning especially these strengths and weaken assumption questions I've chosen five questions for today I'm not really sure if we're gonna get through all five in an hour we're gonna follow up and do another one of these next week so don't worry we'll get to cover a couple more of them so sure but if you could please good put that first one up and once again for anybody who's joining us a little bit late please go to the website link should be up on the YouTube page right now on the live chat please go to the the GMAT Club thread there's a word file on there please download that if you can if you've access to her printer it's gonna make your life a whole lot easier if you've got that sitting next to you I'll give you an extra minute or two on this one a little bit longer for this first one so that anybody who needs to go find that file can do it after I gave you a couple minutes to look this over we'll be back looking at the board so at that point it's gonna be really helpful if you've got this available somewhere else you've got that question up either on paper or up in another window so we'll give you a couple of minutes on this you okay welcome back everybody before we jump back into this question just a quick plug please subscribe to to the d-mat Club YouTube channel that will get live updates whenever we're doing one of these videos or any other live video or any other non live video you'll get updates so please please hit that subscribe button either right now we're soon as we're done today and we're gonna be doing more and more videos over time so this is your chance get on the ground floor while we're doing extra videos okay back to carpentry this question was actually requests from some folks so what do I always want you to do as soon as you this pops up on the screen or as soon as you see that critical reasoning question so we can question your job is to make sure your crystal crystal clear about that conclusion what is it in this case carpenters work on hotels before 1930 typically worked with more skilled care and effort than carpenters who worked on or who have worked on hotels built subsequently now notice a couple things here so I would say notice the modifiers it's really about paying attention to those details of language what do we have here all right worked with more skilled care and effort doesn't say anything about better materials just says worked with more skilled care and effort we're talking specifically about that work in those pre 1930 hotels versus the post 1930 hotels the second thing I always want to do once I'm absolutely clear that I've got exactly their words and that conclusion second thing I want to do is make sure that I understand the reasoning that supports it so why how do they get to this so in those hotels that were built before 1930 the quality of the original carpentry work is generally superior strong language not so strong language not necessarily that comes essential here but those are the kinds of things you want to notice generally superior not a little bit better not just always superior or not superior by itself generally superior it's that kind of thing that makes a huge difference over time that's the habit of mine we want you to develop making sure that you're catching those little details of language so the quality of the result carpentry work is generally superior to that in hotels built afterwards okay before I say anything else I get asked all the time about note-taking so should you write all this crap out when you're actually doing this look everybody's a little bit different I'm not dogmatic at all about what kind of notes you should take what I really care about is are you thinking structurally are you clear about what the heart of the passage is in this case it's a weakened question are you crystal clear a hundred percent clear what's the conclusion exactly in their words not your words do you know how they got there great if you're better off not taking notes great don't take any notes I'm not a huge note-taker by nature what I'm actually taking the test I'll be honest with you I take notes when I'm in trouble on a passage of having a hard time figuring out how the piece of the passage fit together I'll literally do this if I'm in trouble but I feel really really clear about it I'll go through this process in my head and that's it everybody's different my wife is actually a former attorney so she's done tons and tons and tons of ell SATs which has critical reasoning and reading comprehension a little bit harder but very similar to what you see on the GMAT in her case more notes better if she doesn't write notes her brain doesn't work so everybody's a little bit different we'll talk more about this at some point in a future webinar but what should you do to take notes whatever works for you it's a very very individual again for me when I'm in trouble something like this works sometimes people love to do little chart so here's thing a that leads to sink thing B and that leads to a conclusion if you like to draw pictures flowcharts knock yourself out there's no wrong answer here as long as what you're doing number one first and foremost helps you think structurally number two helps you be precise with the language and number three works for you and is efficient don't take notes for the sake of it that's a waste of time take notes what it helps okay so clear enough about kind of what's supporting that conclusion let's run through these answer choices quickly I think everybody's doing pretty well in the live broadcast so answer choice a the quality of original carpentry in hotels is generally far superior to the quality of original carpentry and other structures such as houses and stores who cares everything here is based on the hotels we really don't care about any of those other structures totally irrelevant B hotels built since 1930 can generally accommodate more guests than those built before 1930 once again who cares about the size that has no bearing whatsoever on the quality of the work or the skilled Karen effort of those carpenters Ivy's out see the materials available the Carpenters working before 1930 were not significantly different in quality from the materials after 1930 I think on the GMAT Club thread this is actually the wrong answer that I think was chosen the most frequently touching in a way right because if you miss read this and kind of interpret it to say oh the the quality of the work in general the quality of the carpentry if you think that conclusion is talking about the overall quality of the carpentry and sure maybe look at this and say well it must be true that those materials are relevant somehow in this case we don't really care about it so work with more skilled care and effort if those materials were roughly the same which is what C is saying then that difference must be based on something else right it has to be based on the skilled care and effort of the Carpenters this doesn't do anything actually weaken that conclusion that it's the skilled carrot effort of the Carpenters that was better back in the day there goes C D the better the quality of original cart between a building the less likely that the building is to phone to disuse and be demolished here's the mistake I sometimes see on this one people will say wait a minute we're not talking about demolition that has nothing to do with strength and weaken assumption questions one of the logical features of them is yeah if you're gonna strengthen something chances are pretty good that that thing that's gonna strengthen or that thing that's gonna weaken is gonna be something external something that wasn't explicitly mentioned in the passage already so in this case sure is demolition relevant here so let's think about that better the quality of result carpentry the less likely it is to fall into disuse and be demolished that means we're demotion the ones with crappy carpentry work so when this person who wrote this is walking around visiting hotels which old hotels are still around the ones with better work so that absolutely Kansas's idea that it had something to do with the skilled care and effort of those carpenters it just has everything to do with the fact that the crappy ones from back in the day were demolished all we see is the the ones that had really good work in them so it makes sense that when we look at the existing pre 1930 hotels they have really good quality work keep that one e average length or apprenticeship is decline significantly who cares has nothing to do with it maybe that would explain why the steel Karen effort was better back in the day but that's a huge huge leap you've got to make a bunch of assumptions to think that that's relevant here and certainly doesn't weaken anything all right so these are answer let's move on to the second one and warning to anybody who is trying to avoid questions for the GMAT prep their in the GMAT prep it's the only one we're going to do from the GMAT prep today promise and this is one of the ones I see the most mistakes on so we'll give you a couple of minutes to take a look you okay.we looks like we're getting some agreement on the live broadcast which is fantastic so once again we want you to think structurally it's a strengthened question so you're always looking for the conclusion trying to make sure you get it exactly exactly exactly in their language and just as importantly take a moment invest some time make sure you've got your head completely around what is this thing you're trying to strengthen what exactly is the scope of this thing so here's our conclusion exactly in their words bowerbirds building styles are culturally acquired rather than a genetically transmitted trait okay great I'm basically trying to say that somehow the birds acquire this culturally from each other and it's not something that's just in their DNA somehow what's their evidence to support it different local populations of bowerbirds of the same species build bowers that exhibit different building and decorative styles kind of a mouthful but what's really being compared we're looking at different local populations they have different styles from each other but notice that it also says here of the same species so okay so you've got the bower birds or the same species so presumably genetically similar but different local populations it seems like as these little pockets of birds are doing different things in terms of their building so the evidence says nothing really about differences from species to species it's differences within a species but between different local populations of the bird okay looking for the thing that's gonna strengthen this take a look at a there are more common characteristics and their differences among the bower building styles of local populations that's totally irrelevant so we don't really care sort of within each within that local population that's been studied the most sure there's more and more differences more common more commonality x' than differences but we're within just one local population that has absolutely nothing to do with this we're we're saying that what we care about is that there's differences from one local population to the other a isn't addressing that at all we can get rid of a the young male bowerbirds are inept at Bower building and apparently spend years watching their elders before becoming accomplished in the local Bower style sure that definitely kind of hints that if the male birds need to watch their elders they're learning something it must be culturally acquired so that strengthens it pretty well we'll hang on to be see the bowers of one species of our bird lack the towers and ornamentation of other species once again what are we really comparing here are our evidence is all about within one species how are the local populations doing things differently si is talking about differences from one species to the next has nothing to do with our argument I'm not gonna strengthen it at all I've actually had a few people over the years pick D I'm not sure that anybody's done that in our audience for the live broadcast right now Bera Birds robe found only in New Guinea in Australia where local populations apparently seldom have contact with one another the argument I sometimes see here is well if these local populations don't have contact with one another how could they transmit the trait culturally well but how could they transmitted genetically either so the idea that these local populations rarely come into contact with each other actually does absolutely nothing to distinguish the thing we really care about what's our conclusion about is is Bower building genetically acquired or is it culturally acquired the fact that these local populations don't see each other a whole lot has absolutely nothing to do with it because either way it's not going to transmit very often if these local populations don't have much contact there's nothing to actually address our conclusion there goes D and I think we've had one or two people pick it is well-known that the song dialects of some songbirds are learned rather than transmitted genetically so where are things with Henry say a lot is what do you notice about the language we're gonna suspect the language when I say that I kind of mean what are those little modifiers and most of you have been trained somewhere along the line to look for extreme language for example language in E is an extreme not really but notice a couple things it is well-known that the song dialects of some songbirds are learned rather than transmitted genetically who the heck are some songbirds here notice that they didn't even mention that bowerbirds are songbirds we have no idea if this is relevant at least or bowerbird songbirds or they mute I don't know doesn't say anything about it so some songbirds so some little subset of some birds out there well that's not gonna have anything to do so ever with this so sure some things among some birds are learned what does it have to do with these specific birds in this specific case what's our conclusion bowerbirds building styles specific kind of bird specific building style that's culturally acquired not genetically transmitted so if there's a few songbirds out there that also learn things culturally who knows if that has any bearing whatsoever on these bowerbirds who for all we know might not even be songbirds so that takes care of me and we're left with B alright I think it's gonna do number three I think we probably have time for just two more the way things are gone so we'll skip on the last couple but we'll hit number three next give you guys a couple minutes to take a look you alright sorry for that display issue folks gave you enough time to take a look and I'm hearing some C's and I'm hearing some E's here here's the thing they've done here that starts to get interesting and now the next couple of examples if we have time for all of them we start to get into this whole business of they do a really nice job of either disguising the conclusion or finding a way to kind of tweak the question a little bit so you've got to do some processing and be really clear about what is it you're trying to accomplish here so another week in question here what exactly is the conclusion they've done a little redirect thing here they talked about the inflation rate so opponents of this increase have argued that the resulting rise and wages will drive the inflation rate up that's not the conclusion the conclusion has nothing directly to do with inflation what exactly is the conclusion its impact on wages will probably be negligible that's it there's your conclusion the way I wrote it just to be clearer the increase in the minimum wage from $5 to 550 will probably have a negligible and I can't talk today negligible impact on wages what's the reason to support that really it's just that last little part of that last sentence that's it only a small proportion of all workers in this country currently received less than 550 an hour and that inflation rate thing has really nothing to do with it got something opponents say now if you go through this and try to figure out how exactly this thing's going to impact inflation you're actually barking up the wrong tree because what's the conclusion you care about just wages that's it so if you look at a many people in carlandia who are currently earning the minimum wage have been employed the current job for less than a year I have no idea how that has anything to do with whether wages overall in the economy will rise or not as a result of this change he is out be some firms in carlandia have paid workers considerably less than $5 an hour and violation of the employment regulation this actually kinda has nothing to do with it either because if people are avoiding those minimum wage laws the minimum wage is gonna have absolutely nothing to do with it that actually would support this conclusion that the increase in the minimum wage would have a negligible impact on wages so B actually takes us in the wrong direction kind of subtly because if people are avoiding the law the minimum wage lot doesn't matter nothing's gonna happen does not weaken see many businesses hired trainees I don't hear the minimum wage but must reward trained workers by keeping their pay levels above the pay of trainees okay so now we've got something so this might be true that only a very small proportion of workers currently receive that minimum wage of $5 an hour so their pay is gonna get bumped up but that's not a lot of people but then what si is saying is that then everybody or at least many of the people who who are earning wages a little bit above that they're gonna have to see a bump in their wages so if that means that it's gonna be a much bigger proportion of the workers who get a bump in their wages the ones were finished with training earning more than that $5 an hour originally now all of a sudden it weakens this idea that it's gonna be a negligible impact on wages so let's hang on the C D the greatest growth in curl India's economy has been in those sectors where workers earn wages that are much higher once again that arguably kind a little bit supports the argument if anything because we're saying that hey although the wage growth or all the growth in jobs as in sectors where the minimum wage is it relevant so tiny tiny strengthener for this Saudi is out e the current minimum wage is insufficient for a worker holding only one job fair enough to support a family even when working full-time at that job now I can see where maybe this is a little bit tempting somehow because you're kind of thinking about well maybe if this is the case and it's not enough for people to make a living they've got to have a second job so the minimum wage goes that maybe it kind of has other ripple effects through the economy notice that I'm in this wonderful word world of the word if if I start layering on additional assumptions to this sure maybe you can make a case that this is relevant somehow I don't really see it how would this actually lead to weakening this idea that we just won't move so how does it lead to strengthening the idea that wages actually will change as a result of this minimum wage increase I have no idea how this would actually affect that for that reason he is out and see is your winner I think we have just enough time to get through both of these so if you could play Chevy couldn't pop number four up there and I'll try to move pretty quickly on to the answer choice on this one is the fifth question that we've chosen for today's one of my very very favorite it's actually an LSAT question super super hard illustrates a lot of the kind of core principles that I'd like to talk about so we'll rifle three number four fairly quickly and I think we've got just enough time to get through that five will give you a minute or two on number four you all right and we're back so how do I pick this question I guess it's one of the ones that keeps showing up in our data is one of the hardest critical reasoning questions and the official guide part of it though is that now we're getting in this world of they're not just asking you which of the following would most strengthen the conclusion period they found a way to kind of take that idea of strengthening and turn into this wordy mess in the question stem itself which is the following if true would together with the information above provide the best basis for the claim that the charred bone fragments are evidence of the use of fire by early hominids what's your conclusion here the funny thing they've done yeah this is a strengthened question we want to know kind of which of these answer choices is gonna most reinforce the claim that the charred bone fragments are evidence of use of fire by early hominids that's your conclusion now essentially you're trying to strengthen that conclusion that didn't even appear in the passage it was in the question sneaky and you see that kind of stuff all the time again and we kind of do this thing as test prep folks where we take critical reasoning and we break it down into X number of question types and they're strengthened this week and this assumption there's paradox there's whatever it's a little bit oversimplified that way because the gene that's really really creative about finding ways to take the idea of strengthening but change the question is something that looks a little bit different so there's our conclusion what's their evidence we've got these fragments that scientists have found bone fragments of animals dating back a million years pretty key detail we'll talk about in a moment and they discovered that those have been heated to temperatures no higher than those and campfires made of the stink wood that's found in that area okay so now we want to know what could we add to this that would reinforce that conclusion a the white stink wood tree is used for building materials by present-day inhabitants who cares that has nothing to do with whether they were using fire a million years ago be forest fires can heat wood to a range of temperatures that occur in campfires now it might be kind of tempting right because this is kind of giving you this other idea of what might have heated up the bones now if you think about what it's really doing it's actually weakening it why so scientists found these bone fragments they've been heated to a certain temperature looks like it's evidence that early hominids a million years ago we're using fire but this could also just be natural fire forest fires that happen by accident same range of temperatures as the camp fires B would suggest an alternate explanation for what we're seeing that actually weakens the idea that hominids were using fire a million years ago B's out C bone fragments were fitted together by archaeologists to complete to form the complete skeletons of several animals it sounds really cool but who really cares it doesn't really matter if this was coming from an entire animal or if those fragments were coming from just bits and pieces of them maybe what these early hominids did is they only ate leg meat or something who knows doesn't have anything to do with whether that it was campfires that created those chars on the bone fragments so C is out D apart from the Spartans discovery there's reliable evidence that early hominids used fire as many as five hundred thousand years ago we're talking about a million years ago again we always talk about these little modifiers these little details of language you blow through that one million years all of a sudden D might look pretty good there's there's other evidence that early hominids we're using fire not that early these out and I hope you guys like e and this one makes perfect sense bone fragments were found in distinct layers of limestone that contain primitive cutting tools known to have been used by early hominids notice the reason I I see people discarding e as they'll kind of say well wait a minute there's nothing about bone cutting tools here right we're strengthening this may well feel like it's flying out of left field it might feel like totally outside information and it is in some sense but does it strengthen it does this give us more evidence that maybe this was early hominids a million years ago that caused this charring of the bone fragments in campfires yeah because if you found those bone fragments with cutting tools that presumably were used by hominids then yeah that supports the idea that they were chopping up animals and cooking them it makes perfect sense this reinforces the idea that it was hominids in campfires causing this chart of bone fragments years ago so there's our answer okay I apologize guys we're gonna go a little past the hour mark today we've got one more for you this is an LSAT question it's one of my very very favorites because I think it does a really really nice job of illustrating kind of everything I'm talking about as far as what optimal technique looks like on critical reasoning this one's an assumption question a little bit harder my hunch is that next week same time I'm very very much open to your suggestions come to the GMAT Club forum come to that link that's already posted up on the YouTube page let us know if there's certain questions you'd like to see more of certain kinds of questions related to strengthen or weaken that you'd like to see more more than happy to take your suggestions so we'll probably do more assumption questions next week so certainly this one today but this one does a great job of illustrating all of those core technique pieces think structurally be really precise with the language and just as importantly yeah sometimes on strengths and weaken assumption questions by definition your correct answer feels kind of random comes out of left field your job is to figure out how it connects to that conclusion and that's it so couldn't take a minute or two on this and we'll jump back in you nice it's actually one of the questions that that Mike and I tend to teach to our students that we see the most mistakes on sounds like you guys are doing really well which makes me happy so what's the conclusion here nice and succinct building a Space Station is essential there's a whole lot of other words in there it's not to say they aren't important that's the heart of it building a Space Station is essential for future Mars missions I suppose that's an important detail it's actually very important detail what's their evidence we're gonna need the medical knowledge that the space station project will give us about the limits of human capacities to live in a spacecraft for an extended time that said all the rest of that stuff it's not to say it's not important but that's the heart of it building a space station is essential why we want medical knowledge about the limits of human capacities to live in spacecraft for extended time so what's an assumption that's one of the more awkward questions I think a on the GMAT and really doing so a correct answer here what's a correct answer to an assumption question first and foremost it's kind of in some way reinforce your conclusion it has to right now the problem with it is what makes that a little harder than a strengthen question the strengthen question yeah yeah not a lot of hard logic there whatever it is it's going to reinforce that conclusion great now assumptions sometimes are really really subtle so yes it's gonna strengthen that conclusion but it might do so in a very very subtle way I think of it as sometimes it just paves a really small pothole somewhere in the evidence or it creates a very small bridge sometimes from that evidence to the conclusion sometimes it creates a very obvious bridge from the evidence conclusion you get this whole variety of things at its heart and assumption question is a type of strength in question but the one other thing that's a little bit different is you need it it's not just something that would strengthen but it's something that's absolutely required in order for you to get to that conclusion so think of an assumption question at its simplest as it's a strengthened question but it's a it's a it's something that strengthens your conclusion but you need it need it need it in order to draw that conclusion so let's think about a exploration of Mars will be carried out by people traveling in spacecraft and not by robots alone and the mistake I see over and over and over here robots didn't mention robots this is out of scope this is wrong Spurs the robots wait easy there let's think about how the logic actually works here so if you assume this if you add this to the passage if you kind of insert that assumption here and think about what's gonna happen all right we're gonna need the medical knowledge about the space station the expiration of Mars was gonna be carried out by people after all and not my robots alone therefore building this thing is essential yeah that that reinforces it if it's not true that it's carried out by humans then this whole thing falls apart the only reason we need this space station is because we're gonna send people up there if a is not true we're in big trouble right because if we do send robots why do we need medical knowledge no reason really so we can hang on to a B the capacities of astronauts are typical of those of ordinary human beings one of the things that you hear me talking about all the time modifiers modifiers modifiers might be extreme language you guys have all been trained to see that might be kind of softer language like some or a few or usually or something like that but really any adjective adverb anything it's gonna kind of tweak that scope or strength or quality of something in that answer choice really really matters capacitive astronauts are typical of those of ordinary human beings why do we need to assume that who goes up in his face by definition it's astronauts do we need to assume that those people are ordinary ok doesn't matter at all we need to learn about the limits of human capacities to be in an area in the spacecraft what kind of people go up there astronauts presumably definitely don't need to assume that astronauts are ordinary since they're the only ones that'll ever go up there see no unforeseen medical problems will arise on the first mission to explore Mars unforeseen how does that change things that little modifier no unforeseen medical problems that's actually extreme language which isn't always wrong often an extreme language is totally fine and great and in your correct answers but here let's think about how that affects set no unforeseen medical problems will arise on the first missions what does that mean we know everything already there will be no unforeseen medical problems because we already know about all the medical problems there is – now what does that do to this the whole passage is built on we need the space station because we need medical knowledge si is saying we already have all the medical knowledge we need we can already anticipate everything so what the heck is the point of building a space station to get more no point at all DIA mission to Mars will be the first of many missions that will explore the solar system who cares your conclusion is entirely driven by building a space station it's essential it's gonna give us information we need for future Mars missions not future missions to Jupiter or Pluto because out II living in a spaceship for an extended time presents insurmountable medical problems insurmountable once again those modifiers they get really subtle almost anything is fair game what is insurmountable mean cannot be conquered cannot be surmounted so what kind of medical problems are we talking about hopeless ones so if E is true living in a spacecraft for an extended time is gonna tell us that these these astronauts who are up there they're gonna have maybe they'll die maybe they'll have permanent acid reflux they'll have terrible bunions they'll have hemorrhoids who knows but whatever it is we can't fix it well if we can't fix it what's the point of getting more knowledge it's not going to do anything for us if we build that station Space Station if anybody who goes up there for an extended time will have insurmountable problems that modifier alone that takes care of eat and you're left with a one more quick thing on the assumptions one of the things that that people talk about all the time the gmat Club forums is negation technique on assumptions logically it's totally sound on assumption questions logically it makes perfect perfect perfect sense if the assumption if the correct answer is something you need in order to draw that conclusion then the opposite of it the negation of that answer choice should make that conclusion fall apart logically that's a hundred percent sound that's 100 percent correct now where I'm gonna caution you a little bit on those assumption questions and using that negation technique is I actually think it can be really really hard to figure out exactly what it is that's gonna do the negating if I get to give you a complicated statement there might be multiple ways to negate it so in this case on a the exploration of Mars will be carried out by people traveling in spacecraft and not by abouts alone we could argue this isn't the toughest of them but you could stick that negation almost anywhere in here the exploration of Mars will not be carried out by people traveling in spacecraft or the exploration of Mars will be carried out by people traveling in spacecraft and by robots alone I just removed it or not I negated that last part right that second version of aviation doesn't work very well so for a lot of you that got this right you probably use negation probably used it correctly no problem if you're being a real purist about this the best strongest most reliable way to think about assumptions is to kind of say well what is this due to the conclusion does this reinforce it and do I need it that's what an assumption really is the negation technique can work but as soon as you have a hard time figuring out exactly which piece and gate you might need to turn it just kind of thinking logically about how does this impact the conclusion in a even if you're not thinking about negation technique at all should be pretty easy to see that yeah of course we need to know that it's actually people being sent up if we're doing this for medical knowledge about human capacities to limit spacecraft absolutely we need people going up there and not robots you don't necessarily need the negation technique and on really really slippery questions that negation technique can fall apart it's gonna be good in a whole lot of cases it might not work for you every every time so there's my caution on negation technique on assumptions keep that in the back of your head if as you practice you want to practice not using it great if you want to do some questions using negation not using negation great but just keep in mind it's not 100% reliable just because the Devils in the details what does it mean actually negate any given statement can be really really slippery okay so a quick recap here what do we really care about on critical reasoning in general what you're trying to do is build good habits of mind really think about structure structure structure what's the logical structure in this case all the questions went through today nice clear conclusion somewhere if you change the wording in that conclusion you're toast that's where most mistakes come from changing the wording in the conclusion not being clear about what the conclusion is not being clear about how that evidence supports the conclusion changing words in that evidence keep seeing yourself what she knows about the structure of this passage and second is that my words are their words my words are their words if you're putting words in the passages mouth paraphrasing until it's very very different that's gonna really really change things if you paraphrase too much and let those words adrift and become something different than literally what's on the page you're gonna miss stuff all over the place and it's not sexy people love to kind of hear oh what's my approach different question types what's the formula bad thing about critical reasoning no formulas it's just developing that habit of mind where you really think about a logical structure be precision of language is that their words or my words and am i catching those little modifiers takes time to get better at that really really does if you're having a hard time on critical reasoning be patient with yourself if you really engage in thinking about those key pieces of what it takes to be better at critical reasoning it will get better it might take you a little while but you will get better at it okay that wraps it up for today I start to keep you guys a little bit late next week we will be back same time 7:30 a.m. Pacific time it's kind of be kind of a question and answer type thing most likely based on strength and weaken assumption so good and visit that link if there's certain things you want to see I think we're gonna talk about evaluate the argument questions which are very much a cousin to the assumption strengthen weaken questions anything else you guys want to see let us know we'll try to rope it in time permitting two weeks from today we'll be talking about sentence correction again GMAT punctuation and a lot of the time the punctuation is not worth worrying about that's gonna be the heart of that webinar and then December we're gonna take a little break while I learn how to change diapers my wife is due on December 2nd so probably we won't do any of these videos in December but we have two more left in November so once again folks thank you so much for joining us hit that subscribe button GMAC club gonna be doing more and more of these lectures on admissions on GMAT hit that subscribe button that way you get real-time updates every time we're doing something interesting have fun studying everybody and we'll see on the forums

12 thoughts on “GMAT Critical Reasoning #1 LIVE w/GMAT Ninja: Strengthen, Weaken, & Assumption Questions”

  1. Critical point noted : Assumption comes before the conclusion. (Negation technique can reinforce the solution though).

  2. The main thing I have to improve in CR is doing things structurally and following only stimulus. It was nice video and thanks to gmatclub.

  3. The main thing I have to improve in CR is doing things structurally and following only stimulus. It was nice video and thanks to gmatclub.

  4. A lot of help in this video. For me the most useful is that I have reduced the average time in CR from 2´30´´to 2´ just eliminating notetaking. I focus harder in the conclusion and the why (thinking structurally). Thanks for the video. I am looking for video explanation to reduce time in the Quant part. Let me know if you know something.

  5. great video…but I have a problem with the last question of the video, actually with the answer. I think that choice C is a better than choice A. Because C states that no unforeseen (unpredicted or unexpected) medical problem will arise on the mission to explore mars. Which in turn the writer is assuming, that the medical problems that will appear on the space station are gonna be similar to those which will appear on Mars. That's why writer is assuming that it will be beneficial for the future mars expeditions……… I just think it is logically more correct than choice A. Can you please tell me where I am getting it wrong?

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