1) I really have trouble with Flaw questions in LR. A lot of my mistakes in LR are routinely Flaw questions. I read the question first, so I know its a Flaw. I know most of the general flaws that come up (whole-to-part, correlation equals causation, etc), and can eliminate answer choices that state a Flaw that was not present (i.e. ad-hoc attack), so if it is an obvious example of those clear-cut ones then they are easy. But, sometimes I read the stimulus and can't state exactly what the flaw is/I don't even think it's flawed...is every flaw able to be grouped, and so i just need to be able to recognize that it is a variation of something else? Do you have any general tips for attacking flaw questions, and what to do if I can't easily prephrase an answer? I find that I am often "spinning the wheels" on Flaw question.
Ah, flaw questions. The bane of many a student. Especially since almost all questions are some variation of a flaw question (that's my theory, at least).
For the most part, you can group the flaws into one of those categories (sometimes more than one). However, there are a few times (generally, the trickier ones) where the flaw can really best be understood as an unwarranted assumption, which is just another way of saying a flaw.
If you can't figure out which flaw it is, there are two ways to approach it:
1) Use elements of the premises/conclusion to determine what flaw type is likely. For instance, if you have a really strong conclusion, or a conclusion that recommends one course of action, it's probably an exclusivity fallacy. If you diagrammed the stimulus, it's probably a sufficient/necessary fallacy. If your conclusion is about a member of a group or a group, you probably have a composition fallacy. If you have a study done, it's probably a sampling fallacy. If you have a percentage anywhere in the stimulus, it's probably percentage vs. amount. If you're talking probabilities, it's probably temporal (you're making a prediction of the future based on events in the past, like a roulette wheel). If you conclude that the opposite of someone else's theory is true/false, you probably have an absence of evidence fallacy. If you laughed during the stimulus, you probably have an ad hominem fallacy. If you can underline two sentences that say exactly the same thing, you have circular reasoning (the argument assumes what it purports to establish) - and this is the only time you have circular reasoning. If you compare two things, you probably have a comparative fallacy. If there are quantifiers/modal words (other than never/always, which is probably an exclusivity fallacy), it's probably a logical force fallacy. If you have the words 'thinks' or 'believes' or anything similar, it's probably a perception vs. reality fallacy. If you have a new term show up in the conclusion, it's probably an equivocation. I think that's all of them, but I'm doing this from memory.
2) If you still can't figure it out, try this trick. Say "Even if (premises), it might not be the case that (conclusion)." If you can explain the world in which that statement is true, you'll have your flaw. You may have to go from your specific example of the world where it's not true to a general statement of the flaw, but it should be a lot easier once you've explained a world in which that conclusion doesn't follow from the premises.
2) PT6, S3, Q8. I was debating between B and D, and incorrectly chose B. Can you clarify this? I read the stimulus and thought: ok, WA-> not O. but people say that Obscene WA does exist. But the response is that if it really was O, then its not WA.
I wrote down "claim that WA->O, response is O->not WA" and so I thought that B was correct since it is a contradiction?
You've got the senator's claim right: WA-> NOT O
His response to the counterexamples, however, is O->NOT WA
I don't care what the other people say, because they're not part of the Senator's argument.
Here, the Senator has a general rule, and his response to the counterexamples is to repeat that same general rule (well, the contrapositive of it). Since I can underline the Senator saying the same thing twice (a statement and its contrapositive are the same statement), I've got a circular argument, so D's my answer.
When you wrote down "claim that WA->O, response is O->NOT WA", you neglected to assign those views to different parties. For someone to have a contradictory belief, they have to hold all parts of that contradictory belief. Here, the contradiction is between how others characterize these pieces (as obscene works of art) and how the senator does (obscene non-works of art).
When there exists more than one viewpoint in the stimulus, be very careful to separate the premises into which VP is holding that to be true.
3) PT11, S4, Q17. I got B as the correct answer, since the teacher explicitly says "in which they were made".
but I was wondering why D can't work as well. In fact, when I prephrased it, I thought it would be a straw man flaw since the student starts off by saying "but what you are saying then, is.." and the wording of D seems to be for a straw man attack. And isn't that true? The student is "judging the merits of the teachers position" (i.e. saying the position sucks) because of its ridiculousness in an extreme situation (i.e. you dont need to protect your source because you can just make it up). in this case I chose B over D since it required less of a leap in assumptions. But did I misunderstand what choice D is saying?
But the position of the teacher doesn't apply to just making it up. She's very specific in that she's talking about hiding sources. The student takes that past its credible limits into a world where journalists are just sitting around, quoting no one. You have to deal with the arguments as they're written, and here the teacher clearly states that these journalists are quoting sources, not making it up.
4) PT13, S2, Q24. I don't see how there is an error at all. If only 1 out of 100 times it alerts when there actually was no explosive, then than means the other 99 alerts were correct and there is an explosive, no?
Nope. Let's look at what's going on here, because they're messing with the percentages.
We send a ton of luggage through that scanner. We know that, when there are no explosives present, an alarm goes off ~1% of the time. That means for every 100 pieces of luggage, I get 1 false positive, for every 1000, I get 10, etc...
However, it tells me nothing about how often an actual positive - an alarm goes off when there is explosives - happens. It could be that only 1 time out of a million is there actually an explosive in a piece of luggage (that's probably even a high percentage of the time).
So let's do the math: I put 1,000,000 pieces of luggage through the machine. Since 1/100 times I get a false positive, that means the alarm will go off 10,000 when there is no bomb present. However, if you use my completely made up 1/1,000,000 for the rate of actual bombs, you'll have 1 real bomb. That's much different than the 99% of the alarms that the stimulus makes.
Is it a problem that I just made up a number to test it? No, because the stimulus doesn't tell me that info, so my 1/1million is a possible rate. I've now created a world where the conclusion doesn't follow from the premises (in this case, because they're switching which groups they're referring to when they talk premise percentage and conclusion percentage - premise percentage is based on luggage evaluated, whereas conclusion percentage is talking about luggage that triggered the alarm; different groups, so the percentages don't carry over). Since I now know why the conclusion doesn't work, I can abstract (to my parenthetical from the previous sentence) and find the answer.
Or, I can shortcut it and see that I'm talking numbers and percentages, and I can almost never do that, so I pick the % vs. Amt. fallacy in answer choice E.