Match the structure | Video lesson

- [Instructor] This question asks us, the argument is most parallel in its logical structure to which one of the following? That means we're dealing with a match the structure question. We'll be presented with one argument in the stimulus and then the answer will be an argument that gets to the same kind of conclusion and uses the same kind of evidence to get there. Notice that I say, kind of conclusion evidence. That's because the actual topic doesn't matter when you're matching structures. So go ahead and pause your video now if you want to try to question yourself before I explain it or let's move directly to the explanation if you don't want to try it yourself first. It often helps for match the structure questions if you break the argument down into its conclusion and support. As we read the stimulus, I want you to try to locate what the arguers opinion is and identify why the arguer believes it to be true. The passage reads, it is inaccurate to say that a diet high in refined sugar can not cause adult-onset diabetes, since a diet high in refined sugar can make a person overweight, and being overweight can predispose a person to adult-onset diabetes. So this stimulus is basically one long sentence. And which part of it is our conclusion? It looks like we have a strong signal word for evidence here with the word since. So this part after the word since, is going to be our evidence and that leaves the first part for our conclusion. I like to bracket the conclusions that really stands out to us. It is inaccurate to say that a diet high in refined sugar can not 'cause adult-onset diabetes. Now we ask ourselves why. Why does the arguer believe that a diet high in refined sugar can't 'cause adult-onset diabetes? Well it's because a diet high in refined sugar can make a person overweight and being overweight can predispose a person to adult-onset diabetes. So I see a few terms that repeat in the stimulus which means that we could break this down symbolically. If we call a diet high in refined sugar, x, and we can adult-onset diabetes, z, then this is what our argument looks like. Our conclusion is that it's wrong to say that x can't 'cause z because, and here's our evidence, x can 'cause y, which can 'cause z. If you don't like to think of it symbolically you can describe the structure as, the arguer says that it's wrong to say if something can't 'cause another thing because it's possible that there's an intermediate thing that connects them both. So now we can just find the argument that matches the structure without worrying at all about the topic. These questions can potentially be time-consuming on test day because you're looking at six arguments in total. So one thing we can do is to eliminate any of the choices that don't have the same kind of conclusion that the passage has. So maybe we can get rid of some choices without having to actually read the entire choice. Let's take a look. A, it is inaccurate to say that being in cold air can cause a person to catch a cold. Well we can stop right here. This would match if it said that it's inaccurate to say that being in cold air can't cause a person to catch a cold, but this choice says that it's inaccurate to say that causation can happen. So we can eliminate this one right off the bat. For the record though, the evidence doesn't match either. The choice ends with, since colds are caused by viruses, and viruses flourish in warm, crowded places. There are way more than three terms in this choice. The evidence adds viruses and warm and crowded places. So it's just not a match but we could have stopped at the conclusion on test day. B, it is accurate to say. Nope, nope, stop right there. It is accurate to say, is a confirmation of a belief. But the passage denies a belief. A structure is different so we can rule this choice out. For the record though, the choice in its entirety leads, it is accurate to say that no airline flies from Halifax to Washington. No airline offers a direct flight although some airlines have flights from Halifax to Boston, and others have flights from Boston to Washington. Once again we have way too many terms happening in this choice. And we only had three terms in our relationship from the passage. C, it is correct to say. Nope, this is the same problem that choice b showed. This choice confirms something, it doesn't deny it. The whole choice reads, it is correct to say that over-fertilization is the primary cause of lawn disease, since fertilizer causes lawn grass to grow rapidly and rapidly growing grass had little resistance to disease. So this doesn't work. It confirms that something is the cause of something else, and not only that it's the cause of something else, but it's the primary cause of something else. We want a choice that rejects statement, that denies causation. D, it is incorrect to say that inferior motor oil can not cause a car to get poor gasoline mileage since inferior motor oil can cause engine valve deterioration and engine valve deterioration can lead to poor gasoline mileage. This is a match. The conclusion is the same kind as the passages conclusion and the evidence type matches too. If we map this out symbolically we can call poorer gasoline mileage z. We can call inferior motor oil x. And we can write it out like this. It's wrong to say that x can't cause z since x can cause y and y can lead to z. If you prefer to think of it non-symbolically the arguer is disagreeing with anyone who says that, inferior poor motor oil can't cause poor gas mileage because there's an intermediate cause of engine valve deterioration that connects both of them. That is what's happening in the passage as well. For completion sake let's take a peek at E. It says that it's inaccurate to say that Alexander the Great was a student of Plato. Alexander was a student of Aristotle and Aristotle was a student of Plato. This doesn't match. There's no hint of causation anywhere in the argument so it's not parallel in its logical structure to the passage. So to recap, even though the topics and the choices will usually be different than the topic, in a match the structure has it, it doesn't matter. Your job is to find the argument, the reason, in a way that's similar to how the passage reasons. And a good way to do that is to break down the argument into its conclusion and support. And then eliminate a choice as soon as one of the pieces doesn't match it's corresponding piece in the package. And for the record, don't worry about the order of things. For example, let's say that the stimulus has a conclusion at the end. It's very possible that the answer has the conclusion at the beginning. You're not trying to match style of writing, you're trying to match logical structure. Remember, this same kind of conclusion and the same kind of evidence means that it's your answer.