5 Common Flaws in GMAT Critical Reasoning Arguments | Assumption, Strengthen / Weaken Questions

erricka here with prep scholar GMAT back today with common flaws in GMAT critical reasoning arguments before we get started I want to remind everyone that you can get one-on-one online tutoring from me or another GMAT expert with props color Gina you can head over to our website to sign up or learn more about our other customized online prep options links are in the description and as always if you like this video we've got a lot more great GMAT content so check out our channel and subscribe for updates on new videos and livestreams the most common question types on critical reasoning or strengthen weaken and assumption questions questions in which were asked to evaluate the arguments conclusion or find the flaw in the argument are very similar all of these questions test your ability to locate some sort of weak point in the argument chink in the armor and then do something with that weakness so a strengthened question wants us to find that weakness then solidify it so it no longer damages the argument weakened question wants us to find the weakness then further weaken it so it actively damages the argument an assumption question wants us to find the weakness then identify what needs to be true in order for this weakness not to damage the argument and evaluate the conclusion question wants us to find the weakness then identify what piece of information would help us either strengthen or weaken the argument and then a find the flaw question simply wants us to identify that weakness now there are a bunch of different ways that an argument can be flawed and it's in your best interest to invest time in trying to figure out the weak point in each individual argument before moving on to the answer choices there's a reason that critical reasoning questions should require more time per question than either reading comprehension or sentence correction questions however even though there are a variety of different ways that an argument can be flawed there are several types of critical reasoning argument flaws that appear frequently enough that you should be able to recognize them we'll talk about five of them today the first is correlation versus causation so here's an example people who make flashcards are more likely to pass a test therefore if you want to pass a test you need to make flashcards so this argument assumes that making flashcards is the cause of passing the test this seems likely but it's not necessarily true what if making flashcards has no bearing on passing the test maybe students who are more motivated are both more likely to make flashcards and more likely to pass the test maybe students who are more gifted at time management are both more likely to have time to make flashcards and more likely to have time to finish the test in other words what if making flashcards and passing the tests are only correlated critical reasoning passages frequently assume that if a and B happen at the same time then a causes B when in reality it may be that C causes both a and B you can recognize this flaw by looking for indication that one thing causes or leads to or increases the likelihood of another thing second is misleading statistics let's say there is a university that has recently implemented anti-cheating measured measures designed to decrease the number of cheating incidents at the school after a few years the university indicates that the program has been a success as the percent of students who have cheated has declined by 7 percent this seems pretty logical fewer students cheating leads to fewer cheating incidents however what if the university has also implemented a measure to increase the number of students at the school and the student body is now much larger this means that even if a smaller percent of the student body is cheating the actual number of students cheating may be larger leading to more cheating incidents alternatively it's possible that a few students are responsible for the majority of the cheating incidents maybe a few students cheated on literally every test they had that year but it wasn't discovered until after the fact this means that while the number of students cheating is lower the number of cheating incidents is not these are two classic devil's advocate scenarios for a misleading statistic a statistic that leads you to believe one thing but may not represent the whole picture you can recognize this flaw by looking for statistical information percents and ratios are particularly common misleading statistics third is generalization say a county Parks and Recreation Department is considering building a new park every time the department has built a new park in the past public approval of the department has increased so the department expects that the new parks construction will increase the department's public approval all right what's wrong with this argument well maybe there is a point of diminishing returns on parks maybe the public really only wanted five parks and building any more parks after that won't benefit the public or maybe this park is planned for an area that wouldn't benefit from a park maybe there's another part close by or it's in a neighborhood without many children moral of the story just because something happened in the past or in another location does not mean it's a trend that will continue in the future or in another place you can recognize this flaw by looking for projections this is a really common flaw in plan questions forth is necessary versus sufficient here's an example let's say that a police task force is hiring new staff in order to be qualified for the task force prospective candidates must have completed a certain training program this spring all members of a certain squad will be attending the training program so the task force will be able to recruit their staff from within that squad all right what's wrong here well what if the candidates must also have five years of experience but no one in the squad does what if there is a second training that the candidates must have completed that no one in the squad has gone through in essence if a is required freezy that doesn't mean that a will necessarily lead to Z it's possible that B and C must also occur for Z to even be on the table you can recognize this flaw by looking for if-then language v is imprecise language say that a certain aquarium has an equal number of Tetris and Guppies living in it in may some of the Guppies breed leading to more baby Guppies in the tank by the end of August if none of the tetris bred and none of the Guppies died during this time period then more than half of the fish in the tank at the end of August are Guppies okay what's wrong with this argument seems reasonable if a number of tetras stayed the same and the number of guppies increased the number of Guppies must be greater than the number of tetris right well yeah that's true but that's not the conclusion the conclusion is that the number of Guppies is greater than the number of other fish in the tank what if there are catfish or swordtails in the take in that case we may have four tetras ten Guppies five catfish and three swordtails there are more Guppies and tetris but less than half of the fish in the tank are Guppies critical reasoning arguments are full of sneaky wordplay like this so we need to be on the lookout for it so we can avoid dangerous assumptions we can recognize this flaw by looking for changes in wording what may look like a synonym often isn't now if we can recognize these common fallacies quickly enough we can also use them on other question types to eliminate answer choices that fall victim to these fallacies this is particularly useful for conclusion and inference questions where the wrong answer choices are logically flawed in some way if you have any questions of what we talked about today or suggestions for future videos please leave a comment below thanks for watching and happy GMAT studies

6 thoughts on “5 Common Flaws in GMAT Critical Reasoning Arguments | Assumption, Strengthen / Weaken Questions”

  1. Great job, and thank you for this educative video. The only drawback is that It should be more understandable if you reflected the written forms of the texts that you are delivering verbally.

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