Logical Reasoning Clues/Indicators
Hints that will factor into your ability to handle this type of problem.
Terms in this set (94)
thus, therefore, hence, consequently, as a result, so, accordingly, clearly, must be that, shows that, conclude that, follows that, for this reason.
because, since, for, for example, for the reason that, in that, given that, as indicated by, due to, owing to, this can be seen from, we know this by.
"Additional" Premise Indicators
used to introduce other premises that support the conclusion but are sometimes non-essential to the conclusion furthermore, moreover, besides, in addition, whats more, after all.
Counter Premise Indicators
introduce something that actually contains an idea that is counter to the argument. By raising opposition, the author can minimize the damage that would be done by the objection if it were raised elsewhere. but yet, however, on the other hand, admittedly, in contrast, although, even though, still, whereas, in spite of, despite, after all.
Conclusion Identification Method
Take the statements under consideration and place them in an arrangement that forces once to be the conclusion and the other(s) to be the premise (s). Use premise and conclusion indicators to achieve this end. Once the pieces are arranged, determine if the arrangement makes logical sense. If so, you have the conclusion. If not reverse the arrangement.
an event or circumstance whose occurrence indicates that a necessary condition must also occur.
an event or circumstance whose occurrence is required in order for a sufficient condition to occur.
Words used to introduce a necessary condition
then, only, only if, must, required, unless, except, until, without.
Words used to introduce a sufficient condition
if, when, whenever, every, all, any, people who, in order to.
Primary Objective #1
Determine whether the stimulus contains an argument or if it is only a set of factual statements. MUST recognize whether a conclusion is present.
the unless equation (conditional reasoning)
1. Whatever term is modified by "unless", "except", "until" or "without" becomes the necessary condition 2. The remaining term is negated and becomes the sufficient condition.
Primary Objective #2
If the stimulus contains an argument, identify the conclusion. If the stimulus contains a fact set, examine each fact.
Primary Objective #3
If the stimulus contains an argument, determine whether the argument is strong or weak.
How to determine the strength of an argument
Always ask: Do the given facts support the conclusion? Do the premises strongly suggest that the conclusion would be true? Does the conclusion feel like an inevitable result of the premises? Or Does the conclusion go beyond the scope of the info in the premises? How persuasive is the argument?
Primary Objective #4
Read closely and know precisely what the author said. DO NOT GENERALIZE!.
Primary Objective #5
Carefully read and identify the question stem. DO NOT assume that certain words are automatically associated with certain questions types.
Primary Objective #6
Prephrase: after reading the question stem, take a moment to mentally formulate your answer to the question stem.
Primary Objective #7
Always read each of the five answer choices. If an answer choice appears somewhat attractive, interesting or even confusing, keep it as a contender and move to the next answer.
Primary Objective #8
Separate the answer choices into "contenders" and "loser". After completing this process, review the contenders and decide which answer correct.
Primary Objective #9
If all 5 answer choices appear to be "losers", return to the stimulus and re-evaluate the argument.
3 logical features of conditional reasoning
1. The sufficient condition does not make the necessary condition occur. That is, the sufficient condition does not actively cause the necessary condition to happen. 2. Temporally speaking, either condition can occur first, or the two conditions can occur at the same time. 3. The conditional statement reflected by the author does not have to reflect reality.
Switches the elements in the sufficient and necessary conditions, creating a statement that does not have to be true. Given: A+ --> Study Mistaken Reversal: Study --> A+.
Negates both conditions, creating a statement that does not have to be true. Given: A+ --> Study Mistaken Negation: Not A+ --> Not Study
What to do when a stimulus that contains conditional reasoning is combined with a must be true question stem
Immediately look for the repeat or contrapositive in the answer choices. Avoid mistaken reversals and mistaken negations.
How to approach causality and strengthen questions?
A. Eliminate any alternate causes for the stated effect. B. Show that when the cause occurs, the effect occurs. C. Show that when the cause does not occur, the effect does not occur. D. Eliminate the possility that the stated relationship is reversed. E. Show that the data used to make the causal statements are accurate or eliminate possible problems with the data.
What is the biggest reason students miss questions?
They h ave failed to fully and accurately identify the conclusion of the argument. If a conclusion is present, you MUST identify it prior to proceeding on to the question stem.
Family #1: Prove
Stimulus (accepted) ----> Answer Choices (affected or determined) AKA: must be or prove family must be true, main point, point at issue, method of reasoning, flaw in the reasoning, parallel reasoning.
Family #2: Help
Stimulus (affected or determined) ---> answer choices (accepted) AKA: Help Family assumption, justify the conclusion, strengthen/support, resolve the paradox.
Family #3: Hurt
Stimulus (affected or determined)--/-> answer choices (accepted) Negative sign on the arrow reflects attacking or hurting the argument (weaken).
Family #4: Disprove
Stimulus (accepted) --/-> answer choices (affected or determined) cannot be true.
Rules for Family #1
1. You must accept the stimulus info- even if it contains an error in reasoning-and use it to prove one of the answer choices must be true. 2. Any info in an answer choice that does not appear either directly in the stimulus or as a combination of items in the stimulus will be incorrect.
Rules for Family #2
1. The info in the stimulus is suspect. There are often reasoning errors present and depending on the question, you will help shore up the argument in some way. 2. The answer choices are accepted as given, even if they include "new" info. Your task is to determine which answer choice best meets the question posed in the stem.
Rules for Family #3
1. The info in the stimulus is supect. There are often reasoning errors present, and you will further weaken the argument in some way. 2. The answer choices are accepted as given, even if they include "new" info. The task is to determine which answer choice best attacks the argument in the stimulus.
Main Point Questions
First Family The correct answer choice will be a rephrasing of the main conclusion of the argument. The conclusion is either in the middle or beginning of the stimulus. The correct answer choice must not only be true it also must summarize the author's main point.
LSAT Definition of "either/or"
at least on of the two, possibly both.
Things to remember in regards to WEAKEN questions
1. Stimulus will contain an argument. Must isolate and identify and assess the premises and the conclusion. 2. Focus on the conclusion. Almost all correct Weaken answers impact the conclusion. 3. The info in the stimulus is suspect. There are often reasoning errors present and you must read the argument very carefully. 4. Weaken questions often yield strong prephrases. Be sure to consider the range of possible answers before looking at the answers. 5. The answer choices are accepted as given, even if they include "new" info. Weaken answer choices can bring into consideration info outside of or tangential to the stimulus. CANNOT dismiss answers on grounds of new info.
Weaken question signal words
Weaken, attack, undermine, refute, argue against, call into question, cast doubt, challenge, damage, counter, When evaluating answers ask yourself: "Would this answer choice make the author reconsider his position or force the author to respond?"
Common weakening scenarios
1. Incomplete info. The author fails to consider all of the possibilities or relies upon evidence that is incomplete. This flaw can be attacked by bringing up new possibilities or info. 2. Improper comparison. The author attempts to compare two or more items that are essentially different. 3. Qualified conclusion. The author qualifies or limits the conclusion in such a way as to leave the argument open to attack.
3 incorrect answer traps (weaken)
1. Opposite answers. These answers do the exact opposite of what is needed. 2. Shell game answers. Occurs when an idea or concept is raised in the stimulus and then a very similar idea appears in the answer choices, but the idea is changed just enough to be incorrect but still attractive. 3. Out of scope answers. Simply miss the point of the argument and raise issues that are either not related to the argument or tangential to the argument.
Weakening conditional reasoning
To weaken a conditional conclusion, attack the necessary condition by showing that the necessary condition does not need to occur in order for the sufficient condition to occur. With a combo of a conditional reasoning stimulus and a weaken question, immediately look for an answer that attacks the necessary conclusion.
Words used to introduce cause and effect relationships. (memorize)
caused by because of responsible for reason for leads to induced by promoted by determined by produced by product of played a role in was a factor in is an effect of.
They can be in the premises or conclusion. If they are in the conclusion the argument is flawed. Classic mistaken cause and effect reasoning refers to occurences when a causal assertion is made in the conclusion or the conclusion presumes a causal relationship.
Central assumption of causal conclusions
The makers of the LSAT do not think that there are multiple causes for the same effect. When an LSAT speaker concludes that one occurance caused another, that speaker also assumes that the stated cause is the only possible cause of the effect and that consequently the stated cause will ALWAYS produce the effect.
How to attack a causal conclusion
Whenever you identify a causal relationship in the conclusion of an LSAT problem, immediately prepare to either weaken or strengthen the argument. Tasks for Weaken questions...must always identify a causal conclusion. Then ask if there relationship must be as stated by the author or if another explanation can be found? A. Find alternate cause for the stated effect B. Show that even the cause occurs, the effect does not occur C. Show that although the effect occurs, the cause did not occur D. Show that the stated relationship is reversed E. Show that a statistical problem exists with the data used to make the causal statement.
Fundamental rules for strengthen, justify the conclusion and assumption questions
1. The stimulus will almost always contain an argument you must identify, isolate and assess the premises and the conclusion of the argument 2. Focus on the conclusion. Almost all correct answer choices impact the conclusion 3. The info in the stimulus is suspect. There are often reasoning errors. Read carefully to sure up the argument 4. These questions often yield strong prephrases 5. The answer choices are accepted as given, even if they include new info. Just because a fact or idea is not mentioned in the stimulus is not grounds for dismissing an answer choice.
Strengthen questions ask you to identify the answer choice that best supports the argument. 2 common features
1. The stem uses the word strengthen or a synonym (support, helps, most justifies) 2. The stem indicates that you should accept the answer choices are true.
How to strengthen an argument
1. Identify the conclusion - this is what you are trying to strengthen 2. Personalize the argument 3. Look for weaknesses in the argument 4. 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 5. Remember that the correct answer can strengthen the argument just a little or a lot.
Justify the conclusion formula
Premises + answer choice = conclusion When approaching answers, separate them into winners and losers, then apply the justify formula.
How to identify Justify the Conclusion questions
1. Stem uses the word "if" or another sufficient indicator 2. Stem uses the phrase "allows the conclusion to be properly drawn" or "enables the conclusion to be properly drawn". 3. Stem does not lessen the degree of justification. Never uses "most justifies" or "does the most to justify" Most stimuli contain conditional reasoning or contain numbers and percentages.
How to solve Justify questions mechanistically
1. Any "new" element in the conclusion will appear in the correct answer. 2. Elements that are common to the conclusion and at least one premise normally do not appear in the correct answer. 3. Elements that appear in the premises but not the conclusion usually appear in the correct answer.
Quantity: All = 100 Not all = 0-99 Some = 1-100 None = 0 Time: Always, Not always, Sometimes, Never Space: Everywhere, Not everywhere, Somewhere, No where.
To logically negate a conditional statement, negate the necessary condition. Example: neither...nor becomes either...or.
Typical assumption question stems
1. The stem uses the word assumption, presupposition or some variation 2. The stem NEVER uses the word "if" or any other sufficient condition indicator. The stem will likely contain a necessary condition indicator such as required or unless. The correct answer is a statement the author must believe in order for the conclusion to make sense.
2 roles played by assumptions
Supporter - the traditional linking role, where an assumption connects pieces of the argument. (often new or rogue pieces) They also can close gaps. Ex: All male citizens of athens had the right to vote. Therefore, Socrates had the right to vote in Athens. assumption: Socrates was a male citizen of Athens. Defender - protects the argument by ideas that could weaken the argument. Supporter answer choices lend themselves well to prephrasing. Defenders do not because there are to many possibilities.
Assumption Negation Technique
Allows you to decide between contenders or to confirm that the answer you have chosen is correct. 1. Logically negate the answer choices under consideration. Usually consists of taking a "not" out of a sentence or putting a "not" in a sentence. 2. The negated answer choice that attacks the argument will be the correct answer. When the correct answer is negated, the answer must weaken the argument.
3 quirks of assumption question answer choices
1. Watch for answers starting with the phrase "at least one" or "at least some". When an assumption answer choice starts with one of these phrases it is usually right. But ALWAYS verify with A.N.T. 2. Avoid answers that claim an idea was the most important consideration for the author. Typical structures: "The primary purpose", "the top priority", "the main factor". In every assumption question these answers have been wrong. 3. 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. "no" "not" "never"
Assumptions and conditionality: the two types of answer choices normally produced are?
1. If conditional statements are linked together in the argument, the correct answer choice for an assumption question will typically supply a missing link in the chain or the contrapositive to that link. 2. If you see a conditional conclusion and then are asked an assumption question, immediately look for an answer that confirms that the necessary condition is truly necessary or that eliminates possible alternatives to the necessary condition.
Assumptions and causality: typical correct answer categories
A. Eliminates an alternate cause for the stated effect B. Shows that when the cause occurs, the effect occurs, assumption answers affirm the cause/effect relationship C. Show that when the cause does not occur, the effect doe not occur D. Eliminates the possibility that the stated relationship is reversed E. Shows that the data used to make the causal statement is accurate or eliminates possible problems with the data.
Common features of Resolve the Paradox
1. No conclusion. When a stimulus does not have a conclusion and contains a paradox, expect a Resolve question 2. Language of contradiction exp: but, however, yet, although, paradoxically, surprisingly.
Resolve the Paradox question stem features
1. An indication that the answer choices should be accepted as true 2. Keywords that indicate your task is to resolve the problem Action: Problem: Resolve Paradox Explain Contradiction Reconcile Discrepancy Conflict Puzzle *Attempt to prephrase Correct answer must show how both sides can coexist.
Method of Reasoning questions
1. You can use only the info in the stimulus to prove the correct answer choice 2. Any answer choice that describes an element or a situation that does not occur in the stimulus is incorrect Method of Reasoning questions use a variety of formats, but they all are asking what method, technique, strategy, or process the author is using.
One of the most commonly used stimulus structures is what? How are they recognized?
To raise a viewpoint at the beginning of the stimulus and then disagree with it immediately thereafter. The stimulus often begins with: Some people claim... Some people propose... Many people believe... Some argue that... Some critics claim... Some scientists believe...
A statement or judgement that follows from one or more reasons. Ask: What is the author driving at? What does the author want me to believe? What point follows from the others?
A fact, proposition or statement from which a conclusion is made. Ask: What reasons has the author used to persuade me? Why should I believe this argument? What evidence exists?
Refer to the amount or quantity in the relationship. Examples: (do not need to memorize) all, every, most, many, several, sole, only, not all, none, few.
Refer to the likelihood of occurence or the obligation present, as in "The mayor should resign." "the law will never pass." Examples: (do not need to memorize) must, will, always, not always, probably, likely, would, never, rarely, could, not necessarily. \n
Prephrasing Method of Reasoning questions
Think about the structure of the argument before examining the answer choices. Do not expect to see the exact prephrase, there are too many variations. Make an abstract prephrase then examine each answer to see if it paraphrases the prephrase.\n
1. Appeal to authority - uses the opinion of an authority in an attempt to persuade the reader. The flaw is that the authority may not have relevant knowledge or all of the info regarding the situation, to there may be a difference of opinion among experts as to what is true. 2. Appeal to popular opinion/appeal to numbers - a position is true because the majority believe it to be true. 3. Appeal to emotion - occurs when emotions or emotionally charged language is used in an attempt to persuade the reader.\n
occurs when an author attempts to attack an opponent's position by ignoring the actual statements made by the opposing speaker and instead distorts and refashions the argument, making it weaker in the process. Often prephrased by "what you're saying is" or "if I understand you correctly".\n
General lack of relevant evidence for the conclusion
authors misuses info to such a degree that they fail to provide any info to support their conclusion or they provide info that is irrelevant to their conclusion. \n
Internal contradiction AKA self contradiction
occurs when an author makes conflicting statements. \n
1. The survey uses a biased sample 2. The survey questions are improperly constructed 3. Respondents to the survey give inaccurate responses. People do not always tell the truth when responding to surveys.\n
Exceptional case/over generalization
takes a small number of intstances and treats those instances as if they support a broad, sweeping conclusion. Often appears as an incorrect answer.\n
Errors of composition and division
involves judgements made about groups and parts of a group. an error or composition occurs when the author attributes a characteristic of part of the group to the group as a whole or to each member of the group Error of division - author attributes characteristics of the whole to a part of the group. exp: U.S. wealthiest country. Every American is wealthy.\n
occurs when the author uses an analogy that is two disimilar to the original situation to be applicable. \n
assumes that only 2 courses of action are available when there may be others. \n
Errors in the use of evidence
mis-assessing the force of evidence is a frequent error committed by LSAT authors 1. Lack of evidence for a position is taken to prove that position is false 2. lack of evidence against a position is taken to prove that position is true 3. some evidence against a position is taken to prove that position is false. the introduction of evidence against a position only weakens the position; it does not necessarily prove the position false. 4. some evidence for a position is taken to prove that position is true. \n
Time shift errors
the mistake involves assuming that conditions will remain constant over time, and that what was the case in the past will be the case in the future or present. \n
Numbers and percentage errors
occurs when an author improperly equates a percentage with a definate quantity or vice versa. \n
Uncertain use of a term or concept
as an argument progresses, the author must use each term in a constant, coherent fashion. using a term in different ways is inherently confusing and undermines the integrity of the argument. \n
Source argument AKA ad hominen
this type of flawed argument attacks the person (or source) instead of the argument they advance. because the LSAT is concerned solely with argument forms, a speaker can never validly attack the character or motives or a person; instead, a speaker must always attack the argument advanced by the person. 2 forms: 1. Focusing on the motives of the source 2. Focusing on the actions of the source. \n
the author assumes as true what is supposed to be proved. exp: "this essay is the best because it is better than all the others"\n
Errors of conditional reasoning
mistaken negation and reversal exp: taking the non-existence of something as evidence that a necessary precondition for that thing also did not exist" (MN) "mistakes being sufficient to justify punishment for being required to justify it" (MR)\n
Mistaken cause and effect
1. assuming a causal relationship on the basis of the sequence of events 2. assuming a causal relationship when only a correlation exists 3. failure to consider an alternate cause for the effect or an alternate cause for both the cause and the effect 4. failure to consider that the events may be reversed. \n
Solving Parallel Reasoning questions in the order stated
1. if you recognize the form of reasoning used in the stimulus (causal, conditional, etc.) immediately attack the answers and search for the answer with similar reasoning (analogy, circular reasoning) 2. The Conclusion - match the conclusions, to do so match the certainty level or intent of the conclusion in the stimulus, not necessarily the specific wording of the conclusion 3. The Premises - like the conclusion use the same wording rules. Unless you notice that the premise(s) has an unusual role in the argument 4. The Validity of the Argument - the correct answer choice must match the validity in the stimulus. \n
Fact test for Method of Reasoning questions
If an answer choice describes an event that did not occur in the stimulus, then that answer is incorrect. Watch for answers that are partially true, that is answers that contain a description of something that happened in the argument but that also contain additional things that did not occur. Assess the argument as to it's validity. Be aware of premise and conclusion indicators. This helps better understand the structure of the argument and helps understand the answer choices.\n
Incorrect Method of Reasoning answers
1. new element answers - an answer that describes something that did not occure or describes an element new to the argument cannot be correct 2. Half right, half wrong answers - LSAT makers like to start off with something that happened, then end with something that did not. Half wrong=ALL wrong 3. Exaggerated answers - take a situation from the stimulus and stretch that situation to make an extreme statement that is not supported by the stimulus. Just because an answer choice contains extreme language DOES NOT mean that the answer is incorrect! 4. The Opposite Answer 5. The Reverse Answer - these are attractive because they contain familiar elements from the stimulus, but reverses them in the answer.\n
2 speaker questions
Usually have one male and one female. The female uses sound reasoning and the male uses flawed reasoning or makes a mistake. This is not always true, but more often than not.\n
Method of Reasoning
Argument Part - If you do see the main conclusion at the end of a Method-AP problem, be prepared to answer a question about a part of the arguement other than the conclusion.\n
LSAT Conclusion trick for Method AP questions
They often feature 2 conclusions (main and sub.), when the main conclusion is typically place in the first or second sentence and the last sentence contains the sub. conclusion. The sub. conclusion is set off by conclusion indicators while the main conclusion is not. USE CONCLUSION ID METHOD.\n
Numbers and percentages Common misconceptions
1. Increasing percentages automatically lead to increasing numbers. This is not necessarily true because the overall size of the group could get smaller. 2. Decreasing percentages automatically lead to decreasing numbers 3. Increasing numbers automatically lead to increasing percentages 4. Decreasing numbers automatically lead to decreasing percentages 5. Large numbers mean large percentages and small numbers mean small percentages 6. Large percentages mean large numbers and small percentages mean small numbers. \n
Words used to introduce numerical ideas
amount, quantity, sum, total, count, tally.\n
Words used to introduce percentage ideas
percent, proportion, fraction, ratio, incidence, likelihood, probability, segment, share. \n
Incorrect answers in Point at Issue questions
1. ethical versus factual situations - when the stimulus addresses something ethical, a factual answer would be incorrect and vice versa 2. dual agreement or dual disagreement - often incorrect answer choices will supply statements that both speakers will agree with or that both speakers disagree with 3. the view of one speaker is unknown - test makers create an answer where the view of only one of the speakers in known. Use the Agree/Disagree Test - the correct answer must produce responses where one speaker would say "I agree, the statement is correct" and the other would disagree. If the 2 responses are not produced the answer is incorrect.\n