When it comes to Critical Reasoning on the GMAT, almost every question you'll see will involve arguments. Specifically, the GMAT wants to test you on whether you understand how arguments work.
Understandably, this can be hard to grasp for a lot of students. After all, arguments on the GMAT can be vague, faulty, and difficult to follow. So how can we effectively keep track of what's going on in a Critical Reasoning argument?
Fortunately, there's a very fundamental and structured way that we can view every argument that the GMAT attempts to throw at us. A bit of history first: the GMAT derives its CR questions from the Logical Reasoning (LR) questions on the LSAT (the standardized test for admission into law school) and that part of the LSAT is testing whether students understand syllogistic arguments.
Since the GMAT derives its CR questions from the LSAT's LR questions, this applies to the GMAT Critical Reasoning questions as well; if you understand how syllogistic arguments work, then you'll have a much easier time tackling the CR section.
If you've never heard of this before, don't worry! Basically, every argument that you encounter on the GMAT can be boiled down into two parts: Premises and Conclusions.
A Premise is a stated fact. It's the evidence that's offered in support of a Conclusion.
Any Premise in a GMAT argument is something that is presented as true, and is something that you can never challenge. So, if a Weaken-type question offered an answer choice that attacks a Premise, you can immediately eliminate that answer because you're never allowed to question the validity of a Premise on the GMAT.
However, a Conclusion is actually a form of opinion. It's a judgment that is drawn from the Premises. Thus, a Conclusion can be questioned; in fact, most questions that you'll encounter on the CR section of the GMAT will involve you understanding how the Conclusion can be called into question.
Argument = Premise(s) + Conclusion(s)
A single rule governs this relationship:
Premises support Conclusions.
Now, you might be wondering: Why was "Conclusion" written in plural form? Shouldn't there just be one Conclusion?
Well, for the more difficult GMAT questions that you may encounter, it's very possible for there to be more than one Conclusion present. However, there is only ever one Main Conclusion of an argument. Everything else in the passage is supporting this Conclusion. If a sentence or part (let's call it A) appears to be providing support for another part of the argument (let's call this B), then A is a Premise and B is a Conclusion.
These are the only parts of an argument. Arguments are only made up of Premises and Conclusions, and nothing else. But what about all those other fancy terms such as "evidence, claim, justification, judgment, contention, etc?"
Well, because this relationship is so simple, the GMAT intentionally tries to muddy how straightforward the parts of an arguments actually are by calling Premises and Conclusions by other names. However, each of these terms is just a synonym for Premise or Conclusion.
Evidence, support, justification, etc. are all things that offer support for something else.
Thus, all of these are describing Premises.
Claim, contention, judgment, etc. are all things that require proof. These needs Premises as support.
Thus, all of these are describing Conclusions. Once again, don't be fooled by the language! The GMAT is simply trying to hide how straightforward this actually is.
Remember - when we boil it down to the fundamentals, every argument is only made up of Premises and Conclusions. Premises support Conclusions. Once you have this mastered, it doesn't matter how the GMAT tries to throw you off, you'll know what to look for.
One last note about this: Sometimes a part of an argument could be both a Premise and a Conclusion at the same time.
This is known as an Intermediate Conclusion. It's important to note that this is not the Main Conclusion, but, since most arguments will have only two Conclusions at most, the statement that the Intermediate Conclusion is supporting will usually be the Main Conclusion. The Main Conclusion will be the statement that is supporting nothing else.
Example: A supports B, and B supports C.
In this case, A and B are both Premises, and B and C are both Conclusions.
Specifically, B is an Intermediate Conclusion, and C is the Main Conclusion.
Let's now apply this to a simple example argument:
Bob is a forgetful person. He is exceptionally forgetful when it's raining. It is raining today. Thus, it's likely that he will forget to bring an umbrella on his way to work. Therefore, Bob will probably show up to his workplace drenched.
Notice how the first three statements are just presenting the facts of the situation. From there, we have judgments that are made based on those facts. Thus, the latter two statements are Conclusions that use the Premises as support.
Premise #1: Bob is a forgetful person.
Premise #2: He is exceptionally forgetful when it's raining
Premise #3: It is raining today.
Conclusion #1: Thus, it's likely that he will forget to bring an umbrella on his way to work.
Conclusion #2: Therefore, Bob will probably show up to his workplace drenched.
For each Conclusion, we can ask, "Why?" to determine which Premises were used to support it.
For instance, for Conclusion #1, if we ask why this is the case, we can see that it's using all three of the Premises to come to that judgment. Bob is forgetful, and he is especially forgetful when it's raining, and it happens to be raining. Thus, he will probably forget his umbrella.
For Conclusion #2, if we ask why, we can see that since it's raining, and since he will likely forget to bring his umbrella on his way to work, that he will probably show up to work drenched in rainwater. Thus, Conclusion #2 is using Premise #3 and Conclusion #1 as support.
And, since Conclusion #1 is being used as support, this means that it's serving as both as a Conclusion and as a Premise, which means that it's an Intermediate Conclusion. The statement that the Intermediate Conclusion supports is the Main Conclusion, which is Conclusion #2.