GMAT Preparation

Sentence Correction Basics

2009-09-05T12:57:00.000-07:00

Sentence Correction Basics

Approach to a sentence correction question.

(Later on, we will discuss all the individual things in details )

1. Subject-Verb agreement. As you read the sentence, first identify the subject and the verb; thus also check for agreement as the first thing. (Singular subject has to take a singular verb)

2. Correct usage of tenses: Then as you go on to read the sentence see if proper tense is used. (Especially in past perfect tense and subjunctive constructions)

3. Parallelism: Then checkout for these things- the two sides of idioms must be same. The sentence should not have random changes in tenses.

4. Misplaced modifier: If there are lots of commas in the sentence then probably one of the modifiers must be placed wrongly. The modifier either be an adjective, or be a modifying phrase should be kept as close to the subject it ought to modify as possible.

5. Pronoun agreement and correct reference. The pronoun should clearly (no ambiguity) refer back to its noun and should agree with its noun.

6. The choice should be concise and should not change the original intent of the sentence.

7. Passive reporting should be avoided unless you don't find any other grammatically correct choice.

CR 5. Common fallacies in an argument(contd.)

2009-09-03T13:10:00.000-07:00

Circular Reasoning:

Here, an unsubstantiated assertion is used to justify another unsubstantiated assertion, which is, or at least could be, used to justify the first statement. Their wordings often obscures the fact that buried in one of the premises is the conclusion itself.

This fallacy is also known as circular reasoning, and for good reasoning e.g. Tom: “That’s not important, Jeb.” I know he is telling the truth because he is not lying.

I hope I've made my point clear.

The Biased Sample Fallacy:

The Fallacy of the Biased Sample is committed whenever the data for a statistical inference is drawn from a sample that is not representative of the population under consideration. The data drawn and used to make a generalization is drawn from a group that does not represent the whole.
Here is an argument that commits the fallacy of the biased sample:

In a recent survey conducted by Wall Street Weekly of its readers, 80% of the respondents indicated their strong disapproval of increased capital gains taxes. This survey clearly shows that increased capital gains taxes will meet with strong opposition from the electorate.

The data for the inference in this argument is drawn from a sample that is not representative of the entire electorate. Since the survey was conducted of people who invest, not all members of the electorate have an equal chance of being included in the sample. Moreover, persons who read about investing are more likely to have an opinion on the topic of taxes on investment different from the population at large.

Ad hominen: Attack on character of person. The character of person is logically irrelevant to the truth or falsehood of what he says or to correctness or incorrectness of person’s reasoning. Although, the source of a claim is very important, and you should always consider the credibility of the source before you accept a claim. Ad hominem, however, is different because it asks us to reject a claim based on the person who made the claim, not on any merits of the claim itself. You may thoroughly dislike the person who made the claim, but that doesn’t mean what that person has to say isn’t a good argument or that his or her claim deserves to be automatically rejected. Any time you automatically reject a claim (or ask someone to reject a claim) because of who said it, you commit the ad hominem fallacy. This includes rejecting a claim because it’s inconsistent with something the claim maker has said or done. Just because Sally once cheated on an exam, for example, doesn’t mean you should reject her claim that it’s wrong to cheat. If Sally claims that it’s wrong to cheat and continues to cheat herself, then you have every right to call her a hypocrite. But that doesn’t mean that her claim—that cheating is wrong—is invalid. Keep in mind that people have the right to change their minds and to reject past beliefs or behaviors.

Attack on circumstance of the opponent. There is no relevance / connection between the beliefs held and circumstance of those holding it. Circumstance of one who asserts or rejects the claim has not bearing on claim’s truthfulness. The fact that jury eats meat does not undermine their judgment on a hunter who kills for pleasure that too offending the law.

Accident and converse accident: When we apply a generalization to individual case that it does not properly govern, we commit a fallacy of accident. This is based on truth that what may be generally applicable to group may or may not be applicable to individual. In similar manner, when we apply conclusion drawn on individual cases to general cases, we commit a fallacy of converse accident.

CR 4. Common fallacies in an argument

2009-09-03T13:02:00.000-07:00

COMPARING APPLES TO ORANGES

You may have to look harder to detect an apples-to-oranges comparison. Two questions from the pretest can help demonstrate how common this fallacy is and how to identify it.

Unemployment in Winston County has risen only 4% since I took office. Under my predecessor, unemployment rose 14%. Clearly, my economic policies are far more effective.
Which of the following must be true in order for this argument to be valid?

a. Winston County’s population dropped significantly during the current administration.
b. The national unemployment rate increased by 12% during the previous administration but only 2% during the current administration.
c. Key socioeconomic variables such as the state of the national economy and the demographics of Winston County are comparable for each administration.
d. Key policy changes, such as increased job training for the unemployed, were implemented under the current administration.
e. Tax incentives have been implemented to bring new businesses to Winston County.

The problem here is that unless key variables that affect unemployment are the same during these two administrations, this is a case of comparing apples to oranges. For example, if the predecessor was in office during a deep national recession, no matter how good his economic policies were, he would experience a higher unemployment rate. If Winston County’s economy had been supported largely by a factory that shut down during the predecessor’s administration, this might also explain a significantly higher unemployment rate. The national recession and the factory closing would both have a huge impact on the county’s unemployment no matter who was in office. Without knowing that the variables are nearly the same or without making allowances for differences in those variables, one must assume this is a case of comparing apples to oranges.

The same is true for the question about where to go for heart surgery:

One out of four heart surgery patients at St.Vincent’s dies from complications during surgery. Only one out of six heart surgery patients at St.Mary’s dies from complications during surgery. If you need heart surgery, make sure you go to St.Mary’s, not St.Vincent’s.

Which of the following, if true, is the best reason to reject this argument?

a. St.Vincent’s specializes in heart surgery for elderly and high-risk patients.
b. St.Mary’s surgical equipment is more up to date than St.Vincent’s.
c. St.Vincent’s has the most renowned heart surgeon in the country on its staff.
d. St.Vincent’s offers flexible payment options for balances not covered by insurance.
e. Two doctors who used to work at St.Mary’s now work at St.Vincent’s.

The best reason to reject this argument is the one that shows us this is an apples-to-oranges comparison. To make a fair comparison of mortality rates, the patient base for both hospitals would have to be nearly identical. Because the patients at St. Vincent’s are already at a higher risk for mortality, their mortality rates are necessarily going to be higher—but that doesn’t mean you are less likely to survive surgery there. Assuming you are not an elderly or high-risk patient, to make an informed choice, you would need statistics about St.Vincent’s mortality rates for surgery on patients that are not elderly or high risk.

2. Bandwagon appeals: These are those fallacies that appeal to the human desire to be accepted and belong. They include arguments of peer pressure, bandwagon (join the winning side just because it’s winning), and common practice (it’s okay to do it because everyone else does it). Here is an example:
I know I’m not supposed to take anything from the stock room, but no one saw me take it. Besides, everyone steals stuff from the office once in a while.
This argument suggests that because “everyone steals stuff from the office once in a while,” it’s okay for the speaker to take stuff, too. But just because others do X, that doesn’t make X right.

3. RED HERRING

If you want to distract your listeners from the real issue, you can throw in a red herring (also called a smokescreen)—an irrelevant issue—in the hopes that your listeners will follow that trail instead of the original. For example, look how the following argument uses a red herring to throw the reader off track:

Many citizens will be upset by another tax increase, but we have no other choice. Besides, we live in the best county in the state.

This argument claims the tax increase is inevitable, but instead of offering a premise that supports this conclusion, it changes the subject to bring in an irrelevant issue. Whether or not “we live in the best county in the state” has no bearing on the claim that another tax increase is necessary. This red herring attempts to deflect the matter so that the speaker does not have to explain why taxes should be higher.

4. SLIPPERY SLOPE

The slippery slope fallacy presents an if/then scenario as an absolute. It argues that if X happens, then Y will automatically follow. This “next thing you know” argument has one major flaw, however: X does not always lead to Y. You need to look carefully at the argument to determine whether this is false reasoning (slippery slope) or if a direct and plausible cause/effect relationship really exists between X and Y.

For example, look at the following argument:
If scientists are allowed to experiment with cloning humans, next thing you know, they will be mass producing people on assembly lines. It will be just like Brave New World!
If scientists were to experiment with cloning human beings, for example, does that necessarily mean that humans will be mass produced on production lines? Definitely not. First of all, it may prove impossible to clone healthy humans successfully, no matter how much scientists experiment. Second, if it is possible, it’s a far step from one clone to assembly-line production. Third, if assembly-line production is possible, it will probably not be legal, unless the kind of social / political revolution described in the classic science fiction novel Brave New World occurs. So although the thought of mass-produced human beings is frightening, it’s not logical to restrict experiments because you are afraid of consequences that will probably not occur. You must have other, more logical reasons if you wish to limit that kind of experimentation.

CR 3. Common Questions

2009-09-03T12:56:00.000-07:00

The various types of questions that are asked as follows

1. Find the assumption

The assumption that will be selected should be
a. Closely tied to conclusion
b. Support of strengthen the conclusion

The assumption may be any one of the following
a. Assumptions will serve to fill the gap for achieving the conclusion
b. Assumption can establish the feasibility of the premises of the argument
c. Argument will eliminate the alternative options that are available
d. Argument will eliminate the alternate models of causation

If you are confused in some question and not able to spot the assumption, i.e. it doesn't clearly falls under the above stated categories then you may use- the denial method. It states that if assumption (one of the choices) is false then whole argument should collapse. See which choice if falsified makes the whole conclusion nonsensical.

2. state the conclusion

The conclusion will
a. never go beyond the premises
b. shall not contain any extreme words

3. strengthen the conclusion

The strengthening premises will
a. fix a potential weakness
b. introduces additional supporting evidence

4. weaken the conclusion

The conclusion will
c. expose a faulty assumptions
d. introduce a piece of detracting evidence

5. analyze the argument structure

first recognize the conclusion and then analyze the other argument with keeping in mind the relation of the other conclusion with the main conclusion

6. bridge the paradox

7. evaluate a conclusion

8. Spot similar structure in given examples

CR 2. Approcah to a Question in Critical Reasoning

2009-09-03T12:10:00.000-07:00

Identify Premises and Conclusions

You might be thinking what kind of approach is this, obviously we will do this. But this seems to be most common mistake people make. They start reading the text, then read the question and find out which choice makes the most sense. This method might get you a good accuracy rate( provided you understand the text properly) but will be always a hindrance in getting a very high accuracy rate.

Clearly segregate in your mind what is/are the premise/premises in this question.
what is the conclusion(if one is given)

Have a look at this Que

People should be held accountable for their own behavior, and if holding people accountable for their own behavior entails capital punishment, then so be it. However, no person should be held accountable for behavior over which he or she had no control.

Which of the following is the most logical conclusion of the argument above?
(A) People should not be held accountable for the behavior of other people.
(B) People have control over their own behavior.
(C) People cannot control the behavior of other people.
(D) Behavior that cannot be controlled should not be punished.
(E) People have control over behavior that is subject to capital punishment.

Ans:B

Explanation:

The argument includes the following two premises:
Premise: People are accountable for their own behavior.
Premise: People are not accountable for behavior they cannot control.

If you chose D then you perhaps didn't properly identified the premise and didn't lay much stress in distinction between conclusion and premise.

(A) would require that people never have control over the behavior of other people. Yet the argument does not provide this premise.
(C) would require that people should not be held accountable for the behavior of other people. Yet the argument does not provide this premise.
(D) is not a conclusion; (D) simply reiterates one of the argument's premises (the second sentence).
(E) is not infer-able. The argument allows for the possibility that a person might not have control over another person's behavior which is subject to capital punishment

Although I mentioned in previous post also, but I would repeat the words indicating conclusion.
So...
This shows that...
Therefore...
We can infer that...
Hence...
Consequently...
It follows that...
This indicates that...
For that reason, we may say...
These are phrases that introduce the premises of an argument:
The reason is that...

words indicating premise:

Because...
Since...
Evidence...
On the basis of...
It follows from...
In view of...
We may infer from...

After this, construct inter-relations between all the premises and conclusions given in the question

Put it into your own words( some times it becomes in statements with long worded conclusions and "except" is also given in the question so you have to think on negation basis)

If you follow this segregation method and don't fall into the common fallacies of argument(which we will discuss in subsequent posts)- you are good to go.

CR 1. Critical Reasoning Basics

2009-09-03T10:46:00.000-07:00

Critical Reasoning(CR) questions are one third of the Verbal section of the GMAT exam. These questions are designed to test one's logic and reasoning skills, particularly in evaluating arguments. The questions themselves could deal with almost any subject matter, and no familiarity with that subject matter is assumed or required.( remember this thing clearly because sometimes you can use your own knowledge and go beyond the scope of the question)

Critical reasoning question essentially is of the following structure

(Assumptions) + Premises = Conclusion

Premise is the stated piece of information from which the conclusion is derived.

Assumptions are unstated, but necessary to complete the argument.

Here's an example of a Critical Reasoning text:

A CEO of a major company noted a serious decline in worker productivity during the previous five years. According to a report done by an outside consultant, productivity dropped by 35% by the end of that period. The CEO has therefore initiated a plan to boost productivity by giving employees shares of the company as part of their pay package.

We can use the text above to show the four different parts of a Critical Reasoning text.

Conclusion/Main Idea - Most problems have a central idea or thesis. This is generally located in the sentence at the beginning of the text or in the sentence at the very end. In this case, it is at the end of the passage:

The CEO has therefore initiated a plan to boost productivity by giving employees shares of the company as part of their pay package.

Notice the word therefore in that sentence. Words such as(usage of like here would be grammatically wrong) therefore, thus, hence, as a result , accordingly,consequently, it follows that, and so usually tell us that this is the conclusion or the main idea. Let these words lead you to the main idea.

Premise - Premises are the facts or evidence that support or lead to the conclusion. Unlike assumptions, they are explicit. Here is an example from the text:

A CEO of a major company noted a serious decline in worker productivity during the previous five years.

This premise helps the author lead to the conclusion or main idea of the text. Premise are also identifiable by some words such as since, because, due to, and given that. These words generally describe that this clause/phrase/premise leads to the conclusion.

Assumption- Assumptions are the facts that support the conclusion, like the premise does, but unlike the conclusion and premises they are not stated in the text: they are implicit. Here is what would be an example of an assumption for this particular Critical Reasoning problem:

Owning something or part of something obliges you work harder to make it succeed.

Note that this line is not in the text: it cannot be in the text if it is an assumption of the author. But it does give the argument as a whole some sense, and also supports the conclusion.

Supporting Information- Like a premise, this is stated and explicit information embedded in the text, but unlike a premise, it does not support the conclusion. At best it supports a premise or provides further detail or information regarding a premise. From the text:

According to a report done by an outside consultant, productivity dropped by 35% by the end of that period.

This sentence supports the first sentence, the premise that notes that productivity has dropped. Supporting Information does not support the Conclusion or Main Idea, rather, it supports information that is already in the text.

RC 4. Tone and Pasaage Structure Questions

2009-09-01T17:13:00.000-07:00

Tone Questions:

The question might look like this:

"The author's attitude towards Morgan's theory could best be described as one of..."

Strategy:

Look for descriptive words, adjectives or adverbs, that could tell you the author's attitude. For example, the words unfortunately or flaw suggest a negative connotation, while strength or valuable emphasize the positive. Make brief notes – a couple of words- regarding the Tone of the text on your scrap paper while you read. Additionally, keep in mind that the author's attitude toward a theory, book, or ethnic group will almost always be respectful, even when somewhat critical.

There are lots examples of tones of the author which we shall deal in later posts.

Passage structure Questions:

"Which of the following best describes the organization of the passage?"
"Which of the following best describes the organization of the first paragraph of the passage?"
"One function of the third paragraph is to...."

Strategy:

Re-read the first line of every passage, and the last line of the first and last paragraphs. This should give you the general structure or outline of the argument, with which you can answer the question. Remember to make brief notes about the structure of the text on your scrap paper. If you are looking for the organization of one paragraph, read the first and second sentence of the paragraph. That will give you a rough idea of what is the structure or organization of the paragraph.

RC 3. Specific detail and Infrence Questions

2009-09-01T17:08:00.000-07:00

Specific Detail Questions:

Specific Detail or Target questions are probably the most common types of questions, and the easiest to answer. The question might look like this:

"According to the passage......"
"The passage states that ...."
"The passage supports which of the following....."

Strategy:

The Specific Detail or Target that we are looking for could be a Line Number, or a Name or Date. Go to the Line Number or Name or Date, and then read several lines above and below it. Find the answer choice that basically says the same thing as in the passage, though usually with different words or word order.

Inference Question:

This is probably the most difficult type of Reading Comprehension problem. The question might look like this:

"It can be inferred that the author makes which of the following assumptions?"
"Which is an assumption underlying the last sentence of the passage?"
"Which of the following, if true, would most strengthen the hypothesis mentioned in lines 17-19?"

"With which of the following statements regarding chaos theory would the author be most likely to agree?"

Strategy:

1. First, treat this type of problem as a Specific Target question. Look for a target in the question, find it in the text, and then look above and below it (Read around one line above and below). Often you do not have to infer very much, the answer remains within the text.

2. If the answer must be inferred and is not stated explicitly within the text, then choose the answer choice that can be inferred or assumed from the information given. Again, you should not have to infer very much – only one or two logical steps removed from the information in the passage.

Note: Sometimes thinking too much laterally can also get your question wrong. You have to stick to whatever is stated in the passage and think accordingly. No application of your previous knowledge.

3. Make sure that the answer choice you decide on does not violate or contradict the Main Idea of the passage - if it does, the answer choice is probably wrong.

RC 2. Primary Purpose AND Main Idea

2009-09-01T16:52:00.000-07:00

PART 2: COMMON QUESTIONS

Of the 6 most important types of questions for Reading Comprehension, we will first look at Main Idea/Primary Purpose Questions, and the strategies we can use to answer them.

Note: Many people believe there is no difference between the main or central idea of the passage and the primary purpose of the author of the passage. This is simply not true( in the topic heading also I have written primary purpose and main idea not primary purpose / main idea) . Let's take a look at the subtle but important difference between them

Main Idea
The question might look something like this:

"Which of the following best states the central idea of the passage?"
"Which of the following most accurately states the main idea of the passage?"
"Which of the following is the principal topic of the passage?"
"The main topic of the passage is...."

Primary Purpose
The question might look like this:

"The primary purpose of this passage is to..."
"The primary purpose of the passage as a whole is to..."
"The primary focus of this passage is on which of the following?"
"The main concern of the passage is to..."
"In the passage, the author is primarily interested in...."
"The passage is chiefly concerned with..."

Strategy:

Main Idea:

Look in the first and last paragraphs for the main idea. Any conclusion words like therefore, thus, so, hence, etc. that you see are most likely introducing the main idea. The correct answer will say the same thing as it says in the text, but using different words. The Main Idea is not always stated explicitly in the passage – in fact, more likely than not, it is not stated explicitly. Therefore, in order to answer this type of question when it is more implicit.

1. Re-read the first line of every passage, and the last line of the first and last paragraphs. This should give you the general structure or outline of the argument, with which you can answer the Main Idea question.

2. After determining the general structure or content of the argument, eliminate answer choices that are too broad or too specific, i.e. answer choices that go beyond the content of the passage, or that deal with content only discussed in one paragraph of the passage.

3. Make brief notes – a couple of words- regarding the Main Idea on the text on your scrap paper while you read.

Primary Purpose:

What is the author trying to do? What is his intention? If he is evaluating a theory, then the answer could be something like "Discuss an interpretation". Note that the correct answer would deal with "an interpretation", because the author is only dealing with one theory. If the Primary Purpose is to criticize 2 new books, then his intention or his primary purpose might be to "Critique new studies". Again, as in Main Idea questions, re-read the first line of every passage, and the last line of the first and last paragraphs. This should give you the general structure or outline of the argument, with which you can answer the Primary Purpose question.

Note: A good main idea or primary purpose does not go beyond the scope of the passage, nor does it limit itself to discussing only one part of the passage.

Title Questions:

Title questions are very similar to Main Idea questions, though are less common. Though some of the example passage we use in this tutorial and in the Practice Section are from the New Scientist, and therefore have titles, the passages in the real GMAT will not have titles. The question might look like this:

"Which of the following titles best summarizes the passage as a whole?"

Strategy:

Treat this as a Main Idea question. A good title sums up the central idea of a passage. Therefore, in order to answer this type of question:

1. Look in the first and last paragraphs for the main idea. Any conclusion words like therefore, thus, so, hence, etc. that you see are most likely introducing the Main Idea/Title. The correct answer will say the same thing as it says in the text, but using different words.

2. Re-read the first line of every passage, and the last line of the first and last paragraphs. This should give you the general structure or outline of the argument, with which you can answer the Title question.

3. Make brief notes – a couple of words- regarding the Title on the text on your scrap paper while you read.

4. After determining the general structure or content of the argument, eliminate answer choices that are too broad or too specific, i.e. answer choices that go beyond the content of the passage, or that deal with content only discussed in one paragraph of the passage.

We'll discuss some more of common types in later posts.

RC 1. Reading Comprehension Basics

2009-09-01T16:09:00.000-07:00

PART 1 : FEW BASIC RULES

1. Try to read the whole text of the passage once, if possible:

Many people think you should just skim the passage or read the first lines of every paragraph, and not to read the passage. I believe this is an error: if you misunderstand the main idea of the passage, you will certainly get at least some of the questions wrong. Give the passage one good read, taking no more than 3 minutes to read all of the text. Do not read the passage more than once – that wastes too much time. If you have not understood it completely, try to answer the questions anyway.

2. Make brief notes on the text on your scrap paper:

As we will see below in greater detail, you should write down a couple of words on A) the Main Idea or Primary Purpose, B) Organization/Structure of the passage, and C) the Tone or Attitude of the author (if applicable). You just need a few words for each of these areas, and altogether it should not take longer than 30 seconds to write down.

Note: If this process of scribbling down is taking a lot of time then you can skip this step. But do keep a mental note of the structure and inherent tone of the passage.

3. Try to realize the tone of the passage:

Remember that the tone or attitude of the passage is usually respectful and moderate, never going to extremes of praise nor criticism. ETS obtains its Reading Comprehension passages from real articles about real academics and professionals. So the tone of the articles, even when there is criticism in the passage toward an academic or her work, is always balanced and moderate. In the same vein, articles that deal with minorities or ethnic groups are generally positive and sympathetic.

4. Look out for structural words that tell you the important ideas or transitions in a passage.

Continue the Idea Words:

Similarly
Moreover
Additionally
In the same way
Likewise

Conclusion Words:
Thus
Therefore
Hence
So
In summary
In conclusion

Contradiction or Contrast Words:

Nevertheless
Nonetheless
However
But
Although
Though
Even though
Notwithstanding
Yet
Despite
In spite of
On the one hand…on the other hand
While
Unlike

Note: Whenever these words come in the passage, your mind should automatically get alerted that either some contrast is going to be made( this statement would be wrong in GMAT-SC as it's passive !!!) or some conclusion is about to be drawn. This would keep you on your toes and help your mind not to wander while reading the passage.

5. ALWAYS Go back to the text of the passage for the answers (may be for a fraction of second, but do check your answer with the passage before marking):

Many test-takers fail to return to the text of the passage to look for the correct answers. They rely solely on their memories and understanding of the passage after having read or skimmed it. Wrong. ETS is counting on that. Go back to the text to look for information to answer the questions. Nine times out of ten, the answer lies within the passage.