CHAPTER 8: STRENGTHEN AND ASSUMPTION QUESTIONS

• Strengthen and Assumption questions are considered to be among the hardest Critical Reasoning question types. Assumption questions are variations on the Strengthen theme

In addition to the Primary Objectives, keep these fundamental rules in mind when approaching Strengthen and Assumption questions:

• The stimulus will contain an argument: Because you are being asked about the author’s reasoning, and the reasoning requires a conclusion, an argument will almost always be present.

• In order to maximise your chances of success, you must identify, isolate, and assess the premises and conclusion of the argument.

• Focus on the Conclusion: Almost all correct answer choices impact the conclusion, the better armed you will be to differentiate between correct and incorrect answers

• Information in the stimulus is suspect: There are often reasoning errors present, and you must read the argument very carefully in order to know how to shore up the argument

• These questions often yield strong prephrases. Make sure you actively consider the range of possible answers before proceeding to the answer choices

• The answer choices are accepted as given, even if they include “new” information. Answer choices to the problems in this chapter can bring into consideration information outside of or tangential to the stimulus. Just because a fact or idea is not mentioned in the stimulus is not grounds for dismissing an answer choice

Difference between strengthen and Assumption questions

• Strengthen questions ask you to support the argument in any way possible. The additional support provided by the answer choice could be relatively minor or major.

• Speaking in numerical terms, any answer choice that strengthens the argument, whether by 1% or 100% is correct

• Assumption questions ask you to identify a statement that the argument assumes or supposes. An assumption is simply an unstated premise - what must be true in order for the argument to be true.

• An assumption can therefore be defined as something that is necessary for the argument to be true.

For example:
“An argument concludes that a teenager is an outstanding golfer.”

• In an assumption question, the correct answer could be “The teenager almost always hits the ball” or “The teenager almost never swings and misses the ball”. Either statement is an assumption of the argument; otherwise how could the teenager be an outstanding golfer

• In a Strengthen question, the correct answer could be: “The teenager won a local club tournament”. This answer choice supports the idea that the teenager is an outstanding golfer, but does not undeniably prove the teenager to be outstanding nor is the answer assumption of the conclusion.

Strengthen Questions

• Strengthen Questions ask you to identify the answer choice that best supports the argument. The correct answer doesn’t necessarily justify the argument, nor is the correct answer choice an assumption of the argument. The correct answer simply helps the argument in some way.

• Most Strengthen Questions stems contain 2 features:

  • The stem uses the word “strengthen” or a synonym (strengthen, support, helps, most justifies)

  • The stem indicates that you should accept the answer choices as true, usually with the following phrase:

    • “Which of the following, if true,…”

• Question Stem examples:

  • "Which of the following, if true, most strengthens the argument?"

  • "Which of the following, if true, most strongly supports the statement above?"

  • "Which of the following, if true, does most to justify the conclusion above?"

  • "Each of the following, if true, supports the claim above EXCEPT:"

• How to strengthen an Argument:

  • Identify the conclusion - this is what you’re trying to strengthen

  • Personalise the argument - Personalising allows you to see the argument from a very involved perspective and helps you assess the strength of each answer

  • Look for weakness in the argument - A weak spot in the argument is tailor-made for an answer that eliminates that weakness. If you see a weakness or flaw in the argument, look for an answer that eliminates the weakness. TL;DR - Close any gap or hold in the argument

  • Many strengthen questions require students to find the missing link between a premise and the conclusion. These missing links are assumptions made by the author, and bringing an assumption to light strengthens the argument because it validates part of the author’s thinking.

  • Arguments that contain analogies or use surveys rely upon the validity of those analogies and surveys. Answer choices that strengthen the analogy or survey, or establish their soundness, are usually correct

  • Remember that the correct answer can strengthen the argument just a little or a lot

• 3 incorrect Answer traps (These 3 answer types are not the only ways an answer choice can be attractively incorrect, but they appear frequently enough that you should be familiar with each form):

  • Opposite Answers:

    • These answers do the exact opposite of what is needed - they weaken the argument.

  • Shell Game Answers:

    • A shell game occurs when an idea or concept is raised in the stimulus and then a very similar idea appears in the answer choice, but the idea is changed just enough to be incorrect but still attractive.

    • In Strengthen questions, the Shell Game is usually used to support a conclusion that is similar to, but slightly different from, the one presented in the stimulus

  • Out of scope answers:

    • These answers simply miss the point of the argument and support issues that are either unrelated to the argument or tangential to the argument

• Causality and Strengthen Questions

  • In Strengthen questions, supporting a cause and effect relationship almost always consists of performing one of the following tasks:

    • Eliminate any alternate causes for the stated effect:

      • Because the author believes there is only one cause (stated cause in the argument), eliminating other possible causes strengthens the conclusion

    • Show that when the cause occurs, the effect occurs:

      • Any scenario where the cause occurs and the effect follows lends credibility to the conclusion.

      • This type of answer can appear in the form of an example

    • Show that when the cause doesn’t occur, the effect doesn’t occur:

      • Any scenario where the cause doesn’t occur and the effect doesn’t occur supports the conclusion.

      • This type of answer also can appear in the form of an example

    • Eliminate the possibility that the stated relationship is reversed

      • Because the author believes that the cause and effect relationship is correctly stated, eliminating the possibility that the relationship is backwards (claimed effect is actually the cause of the claimed cause) strengthens the conclusion

    • Show that the data used to make the causal statement are accurate, or eliminate possible problems with the data

      • If the data used to make a causal statement are in error, then the validity of the causal claim is in question.

      • Any information that eliminates error or reduces the possibility of error will support the argument

STRENGTHEN QUESTION TYPE REVIEW

• Strengthen questions ask you to identify the answer choice that best supports the argument

• Use the following points to effectively strengthen arguments:

  • Identify the conclusion - this is what you are trying to strengthen

  • Personalise the argument

  • Look for weaknesses or holes in the argument

• The same type of wrong answer traps appear in Strengthen as in Weaken questions:

  • Opposite answers

  • Shell Game answers

  • Out of scope answers

• In strengthen questions, supporting a cause and effect relationship almost always consists of performing one of the following tasks:

  • Eliminate any alternate causes for the stated effect

  • Show that when the cause occurs, the effect occurs

  • Show that when the cause does not occur, the effect does not occur

  • Eliminate the possibility that the stated relationship is reversed

  • Show that the data used to make the causal statement is accurate, or eliminate possible problems with the data

Assumption Questions (1/3)

• An assumption is simply an unstated premise of the argument; that is, an integral component of the argument that the author takes for granted and leaves unsaid. It is described solely as a linking statement, one that links two premises or links a premise to the conclusion

• Because an assumption is an integral component of the author’s argument, a piece that must be true in order for the conclusion to be true, assumptions are necessary for the conclusion

• The answer you select as correct must contain a statement that the author relies upon and is fully committed to in the argument

• If an answer choice contains a statement that the author might only think could be true, or if the statement contains additional information that the author is not committed to, then the answer is incorrect

• Difference between Assumption questions and Must be True questions can be described as before versus after. Assumption answers contain statements that were used to make the conclusion; Must be True answers contain statements that follow from the argument made in the stimulus. In both cases, however, there is a stringent requirement that must be met: Must be True answers must be proven by the information in the stimulus; Assumption answers contain statements the author must believe in order for the conclusion to be valid.

• Question stem examples:

  • "The argument in the passage depends on which of the following assumptions?"

  • "The argument above assumes that"

  • "The conclusion above is based on which of the following assumptions?"

  • "Which of the following is an assumption made in drawing the conclusion above?"

  • "The conclusion of the argument above cannot be true unless which of the following is true"

• The Supporter/Defender Assumption Model:

  • Assumptions play one of two roles - the Supporter or the Defender

  • The Supporter role:

    • Traditional linking role, where an assumption connects the pieces of the argument.

    • For example:

      • “All male citizens of Athens had the right to vote. Therefore, Socrates had the right to vote in Athens”

      • The linking assumption is that Socrates was a male citizen of Athens. This connects the premise element of male citizens having the right to vote and the conclusion element that Socrates had the right to vote

    • Supporters often connect “new” or “rogue” pieces of information in the argument, and we typically use the term “new” or “rogue” to an element that appears only in the conclusion or in a premise and create gaps in the argument.

    • The conclusion in a supporter argument often contains a piece of information not previously seen in the argument.

    • The Supporter assumption, by definition, closes the hole by linking the elements together. Should you ever see a gap or a new element in the conclusion, a Supporter assumption answer will almost certainly close the gap or link the new element back to the premises.

  • The Defender role:

    • Defender assumptions protect the argument by eliminating ideas that could weaken the argument

    • For example:

      • “People who read a lot are more intelligent than other people. Thus, reading must cause a person to be intelligent”

      • There are a lot of ideas that could undermine this conclusion. The author makes the following assumptions:

        • Sleeping more than eight hours does not cause a person to be intelligent.

        • Regular exercise does not cause a person to be intelligent.

      • These assumptions protect the argument against statements that would undermine the conclusion. In this sense, they “defend” the argument by showing that a possible avenue of attack has been eliminated (assumed not to exist)

  • TL;DR:

    • Supporter Assumption: These assumptions link together new or rogue elements in the stimulus or fill logical gaps in the argument

    • Defender Assumption: These assumptions contain statements that eliminate ideas or assertions that would undermine the conclusion. In this sense, they “defend” the argument by showing a possible source of attack has been eliminated

    • If there is no obvious weakness in the argument and you are faced with an Assumption question, expect to see a Defender answer choice

Assumption Questions (2/3)

• Assumption Negation Technique:

  • You should use the assumption negation technique to decide between contenders or to confirm that the answer you have chosen is correct

  • The purpose of this technique is to take an Assumption question, and turn it into a Weaken question. This technique can only be used on Assumption questions

  • Take the following steps to apply this technique:

    • Logically negate the answer choices under consideration:

      • Alter the sentence so the meaning is logically opposite of what was originally stated

      • Largely consists of taking a “not” out of a sentence when one is present, or putting a “not” in a sentence if one is not present

    • The negated answer choice that attacks the argument will be the correct answer

      • When the correct answer choice is negated, the answer must weaken the argument. This will occur because of the necessary nature of an assumption

      • The consequence of negating an assumption is that the validity of the conclusion is called into question

      • When you take away (negate) an assumption - a building block of the argument - it calls into question the integrity of the entire reasoning structure.

• Do not use the Assumption Negation Technique on all five answer choices. Only apply the technique once you have narrowed the field

Assumption Questions (3/3)

• Three quirks of Assumption Question Answer Choices:

  • Watch for answers starting with the phrase “at least one” or “at least some”:

    • When an assumption answer choice starts with either of the above constructions the chances are unusually high that the answer will be correct.

    • However, if you spot an answer with that construction, do not simply assume the answer is correct; instead use the proper negation (“None”) and check the answer with the Assumption Negation Technique

  • Avoid answers that claim an idea was the most important consideration for the author:

    • These answers typically use constructions such as “the primary purpose”, “the top priority”, or “the main factor”

    • Unless the author specifically discusses the prioritisation of ideas in the stimulus, these answers will continue to be wrong because an author can always claim that the idea under discussion was very important but not necessarily the most important idea

  • Watch for the use of “not” or negatives in assumption answer choices

    • Do not rule out a negative answer choice just because you are used to seeing assumptions as a positive part of the argument

• Assumptions and Causality

  • When a GMAT speaker concludes that one occurrence caused another, that speaker also assumes that the stated cause is the only possible cause of the effect and that the stated cause will always produce the effect

  • The correct answer to an Assumption question will normally fit one of the following categories:

    • Eliminates an alternate cause for the stated effect

    • Shows that when the cause occurs, the effect occurs

    • Shows that when the cause does not occur, the effect does not occur

    • Eliminates the possibility that the stated relationship is reversed

    • Shows that the data used to make the causal statement are accurate, or eliminates possible problems with the data

NEGATING STATEMENTS

• Negating a statement consists of creating the logical opposite of the statement. Logical opposite is the statement that denies the truth of the original statement

  • For example:

    • Original statement: “I went to the beach every day last week”

    • Logical opposite statement: “I did not go to the beach every day last week”

    • Polar opposite statement: “I did not to go the beach any day last week”

• A logical opposite will always completely divide the subject under consideration into two parts.

  • For example:

    • Original statement: Sweet

    • Logical opposite statement: Not sweet

    • Polar opposite: Sour

  • Sweet and sour fail as logical opposites since tastes such as bland or bitter remain unclassified. The correct logical opposite of “sweet” is “not sweet”, which divide the taste spectrum into two complete parts, and tastes such as bland and bitter now clearly fall into the “not sweet” category.

• A number of GMAT questions contain a stimulus that ends with a blank space. No need to worry; on the GMAT these are almost always Assumption questions in disguise. (and when they are not Assumption questions they are Must Be True/Main Point questions)

• The placement of the blank in the stimulus is always at the end of the stimulus. There is a premise indicator at the start of the sentence to help you recognise that you are being asked to fill in a missing premise, which is of course the same as an assumption

• Sample stimulus questions:

  • “…because ____”

  • “…is the fact that ____”

  • “…is that ____”

  • “…since ____”

• Although quite rare on the GMAT, the test makers can offer up “fill in the blank” questions that ask for a conclusion of the argument. In these instances, the blank would be preceded by a conclusion indicator (as opposed to a premise indicator). Fill the blank with the answer choice that best represents the main point of the argument.

• Sample stimulus questions:

  • “Therefore, ____”

  • "Hence, in the new century, the stability of a nation's cultural identity will likely____”

  • "Thus, in many cases, by criminals characterisation of their

    situations, ____”

• As you can see, each sentence above begins with a conclusion indicator that modifies the blank. This is the signal that you must supply the conclusion. Simply look for the answer that best summarises the point of the author’s argument.

ASSUMPTION QUESTION TYPE REVIEW:

• An assumption is simply an unstated premise of the argument; that is, an integral component of the argument that the author takes for granted and leaves unsaid.

• The answer you select as correct must contain a statement that the author relies upon and is fully committed to in the argument.

• On the GMAT, assumptions play one of two roles: the Supporter or the Defender:

  • Supporter Assumption: These assumptions link together new or rogue elements in the stimulus or fill logical gaps in the argument.

  • Defender Assumption: These assumptions contain statements that eliminate ideas or assertions that would undermine the conclusion. In this sense, they “defend” the argument by showing that a possible avenue of attack has been eliminated (assumed not to exist)

• Use the negation technique to decide between Contenders or to confirm that the answer you have chosen is correct.

  • The purpose of this technique is to take an Assumption question, which is generally more difficult, and turn it into a Weaken question. This technique can only be used on Assumption questions.

• Take the following steps to apply the Negation technique:

  • Logically negate the answer choices under consideration

  • The negated answer choices that attacks the argument will be the correct answer

• Negating a statement consists of creating the logical opposite of the statement. The logical opposite is the statement that denies the truth of the original statement, and the logical opposite is different than the polar opposite.

• Assumption answer choices tend to work exactly like Strengthen answer choices in arguments with causal reasoning. Because the author always assumes the stated cause is the only cause, the correct answer to an Assumption question will normally fit one of the following categories:

  • Eliminates an alternate cause for the stated effect

  • Shows that when the cause occurs, the effect occurs

  • Shows that when the cause does not occur, the effect does not occur

  • Eliminates the possibility that the stated relationship is reversed

  • Shows that the data used to make the causal statement are accurate, or eliminates possible problems with the data

• Fill in the blank questions are almost Always Assumption questions in disguise (and when they are not Assumption questions they are Must be True/Main Point questions). The placement of the blank is always at the very end of the stimulus. There is a premise indicator at the start of the sentence to help you recognise that you are being asked to fill in a missing premise, which is of course the same as an assumption. In order to achieve this goal, you must read the stimulus for clues revealing the direction of the argument and the author’s beliefs.