### Archives For Critical Reasoning

My last two articles (part 1 and part 2) gave you some advanced tools to analyze deductive reasoning. Now it’s time to dive into the wonderful world of inductive reasoning, which appears much more often, especially in the following GMAT question types:

• Assumption
• Strengthen
• Weaken
• Evaluate
• Fill in the blank
• Identify the role
• Identify the overall reasoning
• Identify the conclusion
• Mimic the reasoning (sometimes)

According to Wikipedia:

“Inductive reasoning (as opposed to deductive reasoning) is reasoning in which the premises seek to supply strong evidence for (not absolute proof of) the truth of the conclusion. While the conclusion of a deductive argument is supposed to be certain, the truth of an inductive argument is supposed to be probable, based upon the evidence given.”

Therefore, in inductive arguments, conclusions are a matter of opinion, some more strongly supported than others.

Beyond the basics: P.O.S.E.

First, from class and your own study, you should be able to DECONSTRUCT arguments–in other words, identify the background, conclusion, premises, counterpoint, and counter premises of all inductive arguments. Our books cover that skill thoroughly if you need more work.

Next, you should learn to categorize each conclusion by type.

Fortunately, the GMAT uses only a few basic argument patterns, with similar assumptions and a limited number of ways to strengthen or weaken those assumptions. If you can spot and name those patterns, you’re well on your way to drastically improving your CR score.

My last article discussed the difference between inductive and deductive arguments. Today’s article will focus mostly on the rules of deductive arguments. I promise to nerd out on inductive reasoning in later articles.

Here’s a quick quiz on the difference between inductive and deductive logic: http://www.thatquiz.org/tq/previewtest?F/Z/J/V/O3UL1355243858

To review: In a deductively “valid” argument, if all the premises are true, the conclusion must also be true, with 100% certainty. Luckily, on the GMAT, we should usually act as if the premises of an argument are true, especially when the question specifies, “the statements above are true.”

Deductive reasoning shows up most often on inference (aka “draw a conclusion”) questions and “mimic the reasoning” questions, but it often appears on other types of questions, and even on reading comprehension!

On inference questions, the correct answer will usually be deductively valid (or very very strong, inductively). An incorrect answer will be deductively invalid, with some significant probability that it could be false.

What follows are most of the formal rules of deductive reasoning (from a stack of logic textbooks I have on my shelf), with examples from the GMAT. For shorthand, I’ll label the arguments with a “P” for premise and a “C” for conclusion:

P) premise
P) premise
C) conclusion

Remember: these are not the same kind of conclusions (opinions) you’ll see on strengthen and weaken questions. Deductive conclusions are deductively “valid” facts that you can derive with 100% certainty from given premises.

EASY STUFF: Simplification/conjunction (“and” statements)

This is kind of a “duh” conclusion, but here goes: If two things are linked with an “and,” then you know each of them exist. Conversely, if two things exist, you can link them with an “and.”

Simplification:

P) A and B
C) Therefore, A

Conjunction:

P) A
P) B
C) Therefore, A and B

P) Bill is tall and was born in Texas.
P) Bill rides a motorcycle.
C) Therefore, Bill was born in Texas (simplification).
C) Therefore, at least one tall person named Bill was born in Texas and rides a motorcycle (conjunction).

Don’t confuse “and” with “or.” (More about this later.) More importantly, don’t confuse “and” with causality, condition, or representativeness. Bill’s tallness probably has nothing to do with Texas, so keep an eye out for wrong answers that say, “Bill is tall because he was born in Texas” or “Most people from Texas ride motorcycles.”

MEDIUM STUFF: Disjunctive syllogism (“or” statements)

With “or” statements, if one thing is missing, the other must be true.

Valid conclusions:

P) A or B
P) not B (shorthand: ~B)
C) Therefore, A

P) We will go to the truck rally or to a Shakespeare play
P) We won’t go to the Shakespeare play.
C) Therefore, we will go to the truck rally.

Unlike in the real world, “or” statements do not always imply mutual exclusivity, unless the argument explicitly says so. For example, in the above arguments, A and B might both be true; we might go to a play and go to the movies. Yes, really. A wrong answer might say “We went to a play, so we won’t go to the movies.” This error is called “affirming the disjunct.”

Invalid:

P) A or B
P) B
C) Not A

GMAT example:

To see this in action, check out your The Official Guide for GMAT Review 13th Edition, by GMAC®*, question 41. This argument opens with an implied “or” statement:

“Installing scrubbers in smokestacks and switching to cleaner-burning fuel are the two methods available to Northern Power…”

The author here incorrectly assumes that by using one method, Northern Power can’t use both methods at the same time. Question 51 does the same thing; discuss it in the comments below?

TOUGH STUFF: Fun with conditional statements

This is important! Keep a sharp eye out for statements that can be expressed conditionally and practice diagramming them. Look for key words such as “if,” “when,” “only,” and “require.”

I use the symbol “–>” to express an if/then relationship, and a “~” to express the word “not.” Use single letters or abbreviations to stand in for your elements.

So your Critical Reasoning (CR) score has moved a little, but not enough. Or each question is still taking you 3 minutes to answer. You’ve studied for months, read the Strategy Guides, taken every practice test, and completed every Critical Reasoning question in the big Official Guide and the Verbal Review supplement so many times you have them all memorized. What more can you do? Do more questions? You can probably imagine, more questions will usually mean more of the same issues, and simply reinforce bad habits…

Chances are, despite all your hard work, you’re still using your intuition and “gut feeling” to answer CR questions. Unfortunately, your gut feeling works some of the time, but not 100% of the time. Remember, the test is designed so that the average person picking what “looks right” will get only 50% of the questions correct.

So what to do? For now, stop doing more questions until you 1) learn the formal rules of logic behind how CR works, and 2) deeply analyze all the questions you’ve done for repeating patterns: question types, patterns of reasoning, logical flaws, right and wrong answer types, etc.

So that’s what the next few weeks will be about. Each week, I’ll post an article that goes absurdly in-depth about one aspect of the logic behind CR, along with exercises to apply those lessons. These are the same exercises I do with my tutoring students, who have found them very effective. I’m also interested in your feedback: what worked for you? What didn’t? Questions and concepts you’re still struggling with? I’m open to discussion and debate.

So let’s get started. I’ll start with the essentials and then really nerd out on formal logic, so keep reading to the end.

LESSON ONE: RTFQ

In our classes, we teach a four-step process to answering CR questions:

1) Identify the question (Know what the question is asking and what kind of question it is)
2) Deconstruct the argument (Analyze each piece of the passage for what role it plays)
3) Pause and state the goal (Predict what the correct answer should do)
4) Work from wrong to right (Use process of elimination to get to the right–or “least wrong”–answer.)

Today’s focus: Step one, which I call RTFQ, as in “Read the F___ Question” (F as in Full! Read the Full question. What were you thinking?)

The basics: The GMAT only asks a limited number of questions, with very rare variation. Each type of question implies HOW you should deconstruct the argument and WHAT the right answer will do. If you don’t identify the question properly, you won’t look for the right things, or you’ll waste time reading for things that aren’t there. So…Right now, can you name them all? No really.

Exercise 1: Before you scroll down, get out your notebook and write down as many types of questions as you can think of. Ready? Go.
.
.
.
.
.

How many did you come up with? 5? 6? Depending on how you break them down (what books you’ve read and who taught you), there are anywhere from 10-13 common types of questions. Here’s a list of the 11 most common that I use, grouped by category.

Structure based:
Identify the bolded part (role in the reasoning)
Identify the overall reasoning
Identify the conclusion
Mimic the reasoning (also known as parallel the reasoning)

Reasoning/assumption based:
Assumption
Strengthen
Weaken (and Flaw questions)
Evaluate
Fill in the Blank

Evidence or fact-based questions:
Inference (also known as “Draw a Conclusion” questions)
Resolve or Explain (a paradox or discrepancy)

I’ll explain more about the categories in future articles, but for now… Can you identify them when they show up? One of the most common mistakes you can make on the GMAT is simply misidentifying the question (e.g. mistaking strengthen for inference or strengthen for explain).

Exercise 2: Pick a dozen questions and name them! Take out your Official Guide for GMAT Review and get to work. Let’s pick numbers 50 through 61. If you need help, skim the passage itself to (All questions excerpted from The Official Guide for GMAT Review 13th Edition, by GMAC®)

50. Which of the following, if true, most strengthens the argument above?
51. The argument is most vulnerable to the objection that it fails to
52. Which of the following, if true, most strongly supports Summit’s explanation of its success in retaining employees?
53. Which of the following strategies would be most likely to minimize company X’s losses on the policies?
54. If the statements above are true, which of the following must be true?
55. Which of the following most logically completes the argument given below?
56. The conclusion above would be more reasonably drawn if which of the following were inserted into the argument as an additional premise?
57. Which of the following, if true, most helps to explain the surprising finding?
58. Which of the following, if true, most seriously weakens the conclusion above?
59. Which of the following most logically completes the passage?
60. If the facts stated in the passage above are true, a proper test of a country’s ability to be competitive is its ability to
61. Which of the following, if true, does most to explain the contrast described above?

And for good measure, identify number 66.

66. Which of the following conclusions about Country Z’s adversely affected export-dependent industries is best supported by the passage?

Write down what you think each one is.

50. Strengthen: Pretty straight up. The correct answer will strengthen the argument above.
51. Weaken: Or more specifically, identify the flaw in the reasoning. The words “it fails to” mean that the right answer, when considered, will damage the argument.
52. Strengthen: Don’t let the word “explain” fool you. The explanation is already in the argument; in fact the explanation may be the conclusion of the argument. Your job is to find an additional piece of evidence to strengthen that explanation.
53. Resolve/Explain: This one was tough. The question implies that there’s a problem (losses) to be solved (“minimize[d]“), which is what many resolve/explain questions do. Also, the argument itself describes a pretty clear contradiction: how does X keep its prices low, but also make enough income to pay for claims? The answer will resolve this. Feel free to argue with me in the comment section, though.
54. Inference (also known as “draw a conclusion”): Notice how “the statements above are true.” That mean you WON’T be looking for premises and conclusions, just putting facts together to find out what else must be true. More about this later in the section about “Deductive Reasoning.”
55. Fill in the Blank: note that the blank part starts with the word “because____” so you’ll be providing a premise that helps the conclusion. So, in a way, you can look at this as a strengthen question, too.
56. Assumption: Yes, assumption, though if you named this as a strengthen question, you’ll probably get it right. Technically, though, when the GMAT asks for an additional or unstated premise that makes the argument “more reasonably drawn” or that is “required,” it’s asking you for the assumption. But it’s interesting to note that assumption and strengthen questions both do the same thing: support the reasoning of an argument.
57. Resolve/explain: NOT strengthen. Imagine walking into your house to find your favorite chair is broken. Explaining WHY it’s broken is far different from Strengthening or fixing the chair with additional support.
58. Weaken: fair enough, easy to spot.
59. Fill in the blank: and with the word “since____” leading off the blank, it’s another strengthen.
60. Inference: Again, “if the statements above are true…” your reading for facts, not arguments.
61. Resolve/explain: again

aaaaand #66?

66. Inference: Yes. Inference. NOT STRENGTHEN! For more about how to differentiate between Inference and Strengthen questions, see our Critical Reasoning Strategy Guide, chapter 6.

So, how’d you do? If you were less than 100%, spend some time with the strategy guide, focusing on how to identify question types. Write down several examples of each question type and quiz yourself some more. You can use the Official Guide Problem Sets in the back of the CR Strategy Guide to see whether you were right or not. Keep working until you’re 100%.

NERDING OUT ON LOGIC

Critical reason is a test of LOGIC. So, with a big stack of logic books next to me, I’m going to discuss some of the formal rules behind the what GMAT writes questions. Ready?

The GMAT uses the word conclusion in two different ways. Most of the time, the GMAT is referring to an “inductive” conclusion, but occasionally, it’s asking about a “deductive” conclusion. Don’t confuse them!
So to explain: There are two kind of reasoning in the word: deductive reasoning and inductive reasoning.

Deductive reasoning is more concrete, more mathematical, more “true.”

Wikipedia’s definition of deductive reasoning: “Deductive reasoning links premises with conclusions. If all premises are true, the terms are clear, and the rules of deductive logic are followed, then the conclusion reached is necessarily true.”

In other words, if the premises are true, then the conclusion must be true. Does this sound like a common question type? (Hint: it starts with an “I____”)

Here are some examples of deductively valid arguments.

Premise: Sally is taller than Frank.
Premise: Frank is taller than William
Conclusion: Sally must be taller than William.
(Other deductively valid conclusions: Frank is shorter than Sally. William is not the same height as sally.)

Premise: All cats are persnickety
Premise: Mr. Whiskers is a cat.
Conclusion: Mr. Whiskers is persnickety.
(Other deductively valid conclusions: Some persnickety things are cats. At least one cat is named Mr. Whiskers.)

Inductive reasoning is a little softer, and much more common on the GMAT and in the real world. Science, economics, medicine, and our justice system are largely based on induction.

Wikipedia’s definition again: “Inductive reasoning is reasoning in which the premises seek to supply strong evidence for (not absolute proof of) the truth of the conclusion. While the conclusion of a deductive argument is supposed to be certain, the truth of an inductive argument is supposed to be probable, based upon the evidence given.”

In other words, if the premised are true, then the conclusion has a probability of being true, but also a probability of being false.

I’m usually sleepy after 11:00pm.
It’s past midnight.
I must be sleepy.

3 out of 4 dentists recommend chewing OctiDent after meals.
You should chew Octident after every meal.

After I cut bacon out of my diet, I lost 5 pounds.
If you want to lose weight, you should cut bacon out of your diet.

Inductively valid arguments have a very high probability of being true, with little chance of contradictory evidence (good scientific theories). Inductively invalid arguments have a high probability of being false (horoscopes). The dividing line between valid and invalid arguments can be shady and can depend on context. 90% certainty would be a great bet at a casino, but a lousy bet on airplane guidance systems.

We’ll get more into how to evaluate inductive reasoning vs. deductive reasoning in later articles, but for now, lets just learn to spot it.

Exercise: peruse the Official Guide questions 50-61 again. Decide whether the question and argument will be based on induction or deduction (Hint: if the argument can be helped or hurt, it’s probably induction. In the conclusion must be true, it’s deduction.)

50. Which of the following, if true, most strengthens the argument above?
51. The argument is most vulnerable to the objection that it fails to
52. Which of the following, if true, most strongly supports Summit’s explanation of its success in retaining employees?
53. Which of the following strategies would be most likely to minimize company X’s losses on the policies?
54. If the statements above are true, which of the following must be true?
55. Which of the following most logically completes the argument given below?
56. The conclusion above would be more reasonably drawn if which of the following were inserted into the argument as an additional premise?
57. Which of the following, if true, most helps to explain the surprising finding?
58. Which of the following, if true, most seriously weakens the conclusion above?
59. Which of the following most logically completes the passage?
60. If the facts stated in the passage above are true, a proper test of a country’s ability to be competitive is its ability to
61. Which of the following, if true, does most to explain the contrast described above?

50. Induction
51. Induction
52. Induction
53. Induction
54. DEDUCTION
55. Induction
56. Induction
57. Induction (The explanation will be inductively valid.)
58. Induction
59. Induction
60. DEDUCTION
61. Induction

What do you think about question 66? Discuss and debate it in the comments below!

Take some time looking up deductive reasoning vs. inductive reasoning on the web. Wikipedia is a good place to start. Then, start analyzing other questions for the kind of reasoning tested on each. You may find that a lot of the questions you got wrong were one type or the other.

For an advanced drill, dig up all the Inference questions you can find. (I’ll give you a few: 66, 91, 103, and 104) Some of them are asking you for deductively valid conclusions, while others are asking for inductively valid conclusions. Can you determine which is which? Again, post your results in the comments section below.

Get to work, and for now just focus on those questions! See you in future articles.

We’ve been on a CR kick lately! In the first two parts of this series, we talked about how to tackle Fill in the Blank and Complete the Passage questions. This time, I’ve got something different for you: a question that looks very familiar at first glance but turns a bit… well, weird.

Let’s try it before I say anything more. This GMATPrep© problem is from the two free exams that come with the GMATPrep software. Give yourself about 2 minutes (though it’s okay to stretch to 2.5 minutes on a CR as long as you are making progress.)

“On of the limiting factors in human physical performance is the amount of oxygen that is absorbed by muscles from the bloodstream. Accordingly, entrepreneurs have begun selling at gymnasiums and health clubs bottles of drinking water, labeled “SuperOXY,” that has extra oxygen dissolved in the water. Such water would be useless in improving physical performance, however, since the amount of oxygen in the blood of someone who is exercising is already more than the muscle cells can absorb.

Which of the following, if true, would serve the same function in the argument as the statement in boldface?

“(A) world-class athletes turn in record performances without such water
“(B) frequent physical exercise increases the body’s ability to take in and use oxygen
“(C) the only way to get oxygen into the bloodstream so that it can be absorbed by the muscles is through the lungs
“(D) lack of oxygen is not the only factor limiting human physical performance
“(E) the water lost in exercising can be replaced with ordinary tap water”

## Step 1: Identify the Question

The boldface font is immediately obvious, of course. Boldface denotes a Describe the Role question.

The question stem does have one little idiosyncrasy, though: it asks what answer would serve the same function. Normally, Role questions ask what function the boldface statement plays in the argument. The question stem also contains “if true” wording, which we normally see on Strengthen, Weaken, or Discrepancy (paradox) questions.

Glance at the answers. Notice anything? This is not what Role answers typically look like! Usually they say something such as “The statement provides evidence supporting the author’s claim” or similar.

What’s going on here? Read the argument.

## Step 2: Deconstruct the Argument

Here’s what I thought and wrote while I did the problem. Your own thought process won’t be exactly the same as mine and, of course, your notes will probably look quite different, since we all have our own ways of abbreviating things. (Note: R = role; note that I put a question mark next to it because I wasn’t 100% sure what was actually going on).

So back to that weird question stem. If this were just a straight Role question, then what would the answer be? The boldface statement is support for the conclusion; it’s a premise.

But what’s the goal for this question?

Step 3: State the Goal

The answers don’t describe the existing boldface statement. Rather, they contain new facts that we’re supposed to accept as true. Further, the question asked us to find an answer that “would serve the same function” as the original statement.

What function did the original statement serve? Aha! The original statement served as a premise to support the conclusion. So we need to find another statement that serves that same purpose.

Will it support the conclusion in exactly the same way? I’m really not sure. (Seriously! When I first saw this question, I didn’t know!) So I’m going to keep an open mind and look for anything that could support the conclusion in general.

## Work from Wrong to Right

Interesting. We just learned something new. Most Describe the Role (or Boldface) questions ask us to describe the role of the given statement. We might be asked, though, to demonstrate our knowledge of the role by finding a different, completely new statement that serves the same role as the original statement in the argument.

What do we have to do? We have to “decode” the original statement (in the above case, we had a premise supporting the conclusion) and then we have to find another statement that could also serve as a premise.

That new premise might be really different from the original premise. In this problem, the original premise focused on the oxygen already in our blood. The new premise, answer (C), provided a different piece of the puzzle: we have to take oxygen in through our lungs in order to get that oxygen into the bloodstream. Either piece of information serves to support the idea that OXY is useless, but each does so in different ways.

## Take-aways for “Same Function As” Role Questions:

(1) The standard task on role questions is to describe the role of the statement given in the argument.

(2) You might see a variation on this standard task: you may be asked to find a new statement that plays the same role as the original.

(3) This new statement may discuss a different aspect of the argument. That’s perfectly all right as long as the statement overall plays the same role as the original boldface statement.

* GMATPrep® questions courtesy of the Graduate Management Admissions Council. Usage of this question does not imply endorsement by GMAC.

Last time, we talked about Fill in the Blank CR questions: what are they and how do we tackle them efficiently? If you haven’t already read that article, go ahead and do so.

Then, come back here and test your new-found skills on this GMATPrep© problem (it’s from the two free exams). Give yourself about 2 minutes (though it’s okay to stretch to 2.5 minutes on a CR as long as you are making progress.)

“Which of the following best completes the argument?

“A new machine for harvesting corn will allow rows to be planted only fifteen inches apart, instead of the usual thirty inches. Corn planted this closely will produce lower yields per plant. Nevertheless, the new machine will allow corn growers to double their profits per acre because ________________

“(A) with the closer spacing of the rows, the growing corn plants will quickly form a dense canopy of leaves, which will, by shading the ground, minimize the need for costly weed control and irrigation
“(B) with the closer spacing of the rows, corn plants will be forced to grow taller because of increased competition for sunlight from neighboring corn plants
“(C) with the larger number of plants growing per acre, more fertilizer will be required
“(D) with the spacing between rows cut by half, the number of plants grown per acre will almost double
“(E) with the closer spacing of the rows, the acreage on which corn is planted will be utilized much more intensively than it was before, requiring more frequent fallow years in which corn fields are left unplanted”

## Step 1: Identify the Question

The blank line tell us that we have an argument in the “complete the passage” format.

I was talking to a student today about Complete the Passage CR arguments (people also call these the Fill in the Blank questions). The student was struggling with these and talking about them as though they were their own category. The problem: they’re not actually a separate category at all!

Try this GMATPrep© problem out (it’s from the free set that comes with the software) and then we’ll talk about it. Give yourself about 2 minutes (though it’s okay to stretch to 2.5 minutes on a CR as long as you are making progress.)

“Which of the following best completes the passage below?

“People buy prestige when they buy a premium product. They want to be associated with something special. Mass-marketing techniques and price reduction strategies should not be used because ________________

“(A) affluent purchasers currently represent a shrinking portion of the population of all purchasers
“(B) continued sales depend directly on the maintenance of an aura of exclusivity
“(C) purchasers of premium products are concerned with the quality as well as with the price of the products
“(D) expansion of the market niche to include a broader spectrum of consumers will increase profits
“(E) manufacturing a premium brand is not necessarily more costly than manufacturing a standard brand of the same product”

## Step 1: Identify the Question

The blank line immediately leaps to eye of course: as soon as you see that, you know you have an argument in the “complete the passage” format.

What kind of question type is it? Actually these fall into one of the regular types that you already know: Strengthen, Weaken, Find the Assumption, Inference, and so on. The trick is that it’s a bit harder to tell which type.

The majority of Complete the Passage questions are Strengthen. The second most common category is Find the Assumption. Typically, if you see the word because or since right before the underline (as in this problem), then you probably have a Strengthen question. The word because (or since) indicates that the correct answer will add a piece of evidence to support some statement. You’ll need to read the argument to be sure, but you can have a pretty strong hunch.

## Step 2: Deconstruct the Argument

This is likely a strengthen question, so it should contain a conclusion.

Here’s what I thought and wrote while I did the problem. Your own thought process won’t be exactly the same as mine and, of course, your notes will probably look quite different, since we all have our own ways of abbreviating things. (Note: S = strengthen; at first I put a question mark next to it because I wasn’t 100% sure until I finished the argument.)

If the conclusion is NOT to use mass-marketing techniques and price reduction strategies because of some reason, then that reason must support that conclusion. This is, indeed, a Strengthen question.

## Step 3: State the Goal

The goal on Strengthen questions is to find a new piece of information that makes the conclusion at least a little more likely to be valid. I’m trying to validate the idea that you should NOT use certain strategies. (Note: in Complete the Passage format, sometimes the correct answer won’t really be new; it will mostly just restate something that the argument already said. This is acceptable as long as it strengthens!)

Why not? The first two sentences said that premium products are all about prestige and “something special.” If you’re trying to sell premium products, then, mass-market techniques probably aren’t going to make people feel “special.” Likewise, a reduction in price doesn’t scream “premium product!” We expect premium products to cost more and we don’t expect everyone in the world to have them.

I’m going to keep that in mind while I examine the answers!

## Work from Wrong to Right

Note that answers (A) and (D) both seem to go along with the idea that we might want to use mass-marketing techniques or price-reduction strategies. Both are trap answers designed to catch someone who didn’t notice or forgot that the conclusion says these strategies should NOT be used.

Looking for more help on Critical Reasoning? Check out the Master Resource List for Critical Reasoning.

## Take-aways for Complete the Passage formats:

(1) These are not a separate question type. A “complete the passage” question falls into one of the same categories as all other questions; you have to figure out which it is.

(2) Most often, these questions are Strengthen (as in the above case) or Find the Assumption. If you see the word because or since right before the underline, you probably have a Strengthen question. If you see something else, then you may have an Assumption question instead.

(3) As with any CR question, the key is to identify the type of question and follow the standard process from there!

* GMATPrep© questions courtesy of the Graduate Management Admissions Council. Usage of this question does not imply endorsement by GMAC.

Is that a comparison?

One way to classify conclusions on GMAT Critical Reasoning conclusions is comparative versus absolute.  Why should you care about this classification?  Because this distinction can be very helpful in eliminating wrong answers and finding right answer.

A comparative conclusion will make a comparison between two or more groups.

Car A is better family car than Car B.

An absolute conclusion will just express an opinion about one specific topic or situation.

Therefore, A monorail should not be installed in Town C’s central district.

As a start, let’s get used to classifying conclusions as absolute or comparative.  If the conclusion is comparative, identify the two groups being compared.

1) Therefore, children in the United States who spend at least two hours a day outdoors are less likely to be obese than other children.

2) Thus, Springfield’s recycling program is likely to achieve its aim.

3) For these reasons, isolationism should not be considered a viable trade strategy.

4) The service sector will become more important to Caloda’s economy in the future.

5) Brand D is the best brand of vacuum cleaner available.

(See bottom of this post for answers)

Now that you are comfortable identifying different types of conclusions, we will consider how this classification will help you find the right answer. In many critical reason question types, your job in finding the answer is to influence the conclusion (strengthen the conclusion, weaken the conclusion, find the assumption).  Let’s consider answer choices that are most likely to influence these different types of conclusions. Continue Reading…

Some interesting —and alarming—articles have been making the rounds lately, following on the heels of an academic study published by professors at the University of Akron and Cleveland State University. The more reputable articles report such sweeping conclusions that I actually wondered whether the journalists got it wrong, so I went to the source (I can link only to the abstract here, but I did read the full study).

When I read the study’s methodology, I knew I had my next article topic. We’re going to test our Critical Reasoning (CR) skills on an actual academic study! You might have to do something similar in business school (admittedly with a business case, not an academic study), so let’s test your b-school readiness now!

(Note: I refer to the “more reputable articles” because some blogs have picked this up and publishing under headlines such as “Is the GMAT the root of all evil?” As much as you may hate studying for this test, I think we can agree that this characterization is a bit over the top. : ) )

## Correlation vs. Causation

We need to define a couple of terms first. You may already have learned about correlation and causation in your CR studies; here’s a refresher.

Correlation: two phenomena tend to occur or appear at the same time or in conjunction with one another

Causation: one phenomenon causes another phenomenon

Correlation does not imply causation. One of two correlated phenomena could cause the other but those two things could also have absolutely no causation between them. Alternatively, the two things could both be caused by a third thing. The two things could even cause each other! (Predator-prey dynamics are an example of this kind of two-way dependency.)

For example, have you ever noticed how, when the ground is wet, people often seem to be carrying around umbrellas? Those two phenomena are correlated. Which one causes the other? Continue Reading…