Logical Reasoning Flashcards
Flaw
Question Type Overview:
These questions ask you to identify the error in reasoning. The error often involves a logical fallacy or assumption that weakens the argument’s strength.
Stem Examples:
* “The reasoning in the argument is flawed because it…”
* “Which one of the following most accurately describes a flaw in the argument?”
How to Approach:
* Identify the premises and the conclusion.
* Spot the flaw: Is the reasoning assuming something unproven? Is there a logical jump?
* These questions often require you to understand why the conclusion does not follow from the premises.
Do You Need to Find the Gap?
* Yes, often the flaw is where the argument overlooks or assumes something essential.
Common Traps to Avoid:
* Be careful not to pick answers that describe minor flaws, such as inconsequential details or peripheral points. Focus on the central error.
* Don’t be misled by answers that describe the argument as having a contradiction or being confusing — the flaw is typically more structural.
Correct Answer Includes:
* The answer will describe a logical inconsistency or invalid assumption that undermines the connection between premises and conclusion.
Weaken
Question Type Overview:
Weaken questions ask you to find an answer that undermines the argument’s validity by challenging the reasoning or evidence.
Stem Examples:
* “Which one of the following, if true, would most weaken the argument?”
* “Which one of the following statements calls into question the argument?”
How to Approach:
* Understand the conclusion and its supporting premises.
* Look for an answer choice that casts doubt on the strength or truth of the argument.
* Be cautious of answers that only weaken tangential points; focus on answers that directly challenge the core logic.
Do You Need to Find the Gap?
* Yes, find where the argument’s reasoning could be undermined or insufficient.
Common Traps to Avoid:
* Avoid answers that provide additional supporting evidence. This is not the point of a weaken question.
* Don’t pick answers that only clarify or expand on existing premises without challenging the logic.
Correct Answer Includes:
* The correct answer will introduce new information or point to an assumption that, if true, would undermine the conclusion’s validity.
Strengthen
Question Type Overview:
These questions ask you to find an answer that bolsters the argument by providing additional support for the conclusion.
Stem Examples:
* “Which one of the following, if true, would most strengthen the argument?”
* “Which of the following statements would most help the argument?”
How to Approach:
* Identify the main conclusion and the premise(s).
* Find the answer choice that directly strengthens the link between the premise and the conclusion.
* Look for an answer that removes uncertainty or provides more compelling evidence in favor of the conclusion.
Do You Need to Find the Gap?
* Yes, you need to find where the argument’s reasoning could be made stronger.
Common Traps to Avoid:
* Don’t select answers that introduce unrelated facts that don’t strengthen the logical connection.
* Avoid answers that simply restate or reword part of the argument without adding anything new.
Correct Answer Includes:
* The correct answer will provide direct support for the argument’s reasoning, making the conclusion more likely or more believable.
Necessary Assumption
Question Type Overview:
These questions ask you to identify an assumption that must be true for the argument to hold. If the assumption is false, the argument collapses.
Stem Examples:
* “Which one of the following is an assumption required by the argument?”
* “Which one of the following must be assumed in order for the conclusion to be properly drawn?”
How to Approach:
* Identify the premises and conclusion.
* Consider what hidden assumption is necessary for the argument’s logic to work.
* The necessary assumption is something that, if false, would destroy the argument’s reasoning.
Do You Need to Find the Gap?
* Yes, you need to identify the assumption that connects the premise to the conclusion.
Common Traps to Avoid:
* Avoid answers that introduce new facts or irrelevant information that don’t directly impact the conclusion.
* Don’t pick answers that strengthen the argument; the necessary assumption is something that the argument cannot survive without.
Correct Answer Includes:
* The correct answer will be an assumption that, if false, would invalidate the entire argument.
Sufficient Assumption
Question Type Overview:
Sufficient Assumption questions ask you to find an assumption that, if true, guarantees the conclusion.
Stem Examples:
* “The conclusion of the argument follows logically if which one of the following is assumed?”
* “Which one of the following, if true, would allow the conclusion to be properly drawn?”
* “Which of the following is an assumption that, if true, would guarantee the conclusion?”
How to Approach:
* Look for an answer choice that completes the reasoning and makes the conclusion undeniable.
* The answer should be something that fully bridges the gap between premise and conclusion.
Do You Need to Find the Gap?
* Yes, you need to find the assumption that completes the logical gap and makes the conclusion certain.
Common Traps to Avoid:
* Avoid answers that weaken the argument or introduce new information that doesn’t directly guarantee the conclusion.
* Be careful not to choose general assumptions that don’t resolve the gap between premise and conclusion.
Correct Answer Includes:
* The correct answer will be an assumption that, if true, 100% ensures that the conclusion follows logically from the premises.
Parallel Reasoning
Question Type Overview:
Parallel Reasoning questions ask you to find an argument that has a reasoning pattern similar to the argument in the stimulus.
Stem Examples:
* “Which one of the following is most similar in reasoning to the argument above?”
* “Which one of the following exhibits a pattern of reasoning most similar to the argument above?”
How to Approach:
* Focus on the structure of the argument. Don’t get distracted by the content — focus on how the conclusion is supported.
* Match the logical structure of the argument, paying attention to whether the premises and conclusion are connected in the same way.
Do You Need to Find the Gap?
* No, this type doesn’t require finding a gap in reasoning, but you need to match the reasoning pattern.
Common Traps to Avoid:
* Don’t pick answers that are similar in content but not in reasoning. Focus on matching the methodology, not the details.
* Avoid choosing answers where the conclusion is supported in a completely different manner.
Correct Answer Includes:
* The correct answer will match the logical structure of the argument, with the same type of reasoning used.
Step-by-Step Method for Parallel Reasoning (Structure Matching)
- Break the stimulus into parts:
Write down (mentally or physically) this basic structure:
• Premise(s)
• Conclusion
• Reasoning Type
• Key Logical Operators (e.g., if/then, some, all, must, not)
You want to be super mechanical here. Don’t gloss over these. Missing a “some” vs. “all” or a conditional structure is usually what makes people pick the wrong answer.
- Label the reasoning type:
This is what really helps with consistency.
• Conditional reasoning? Look for chains like: If A → B. A. Therefore, B.
• Causal? Something like: X happened after Y. Therefore, Y caused X.
• Analogy or comparison? The author is likening two situations.
• Elimination? Ruling something out by pointing to an alternative.
Try to name what the reasoning is doing. If you can’t name it, odds are you’ll struggle to match it.
- Match conclusions FIRST:
This is the most important tip. The correct answer must draw the same type of conclusion as the stimulus: same strength (definite vs. probable), same structure.
Examples:
• If the stimulus says, “Therefore, X must be true,” don’t pick an answer that says “X probably is true.”
• If the stimulus says, “Since no A is B…” the correct answer will use a “none” or “never” structure.
- Match logical structure (quantifiers, conditionals, negations):
This is where most mistakes happen. The correct answer must match:
• The number of premises.
• The logical relationship between ideas (e.g., if/then, some, all, not both).
• Whether anything was reversed or negated.
Even a tiny mismatch in structure makes the answer wrong.
Bonus Tips:
• Eliminate by difference: Wrong answers often look similar in content or topic, but contain different logic. Look for mismatched strength (must vs. might), flipped logic (converse/inverse errors), or different conclusion types.
• Ignore topic, 100%. Don’t get caught up in new ideas like “aliens” or “philosophy.” Stay glued to the logic.
• Use shorthand if needed: Write symbols like:
• A → B, A ∴ B
• No A is B
• Some A are B
Method of Reasoning
Question Type Overview:
These questions ask you to describe the method of reasoning used in the argument. You need to recognize how the conclusion is supported by the premises.
Stem Examples:
* “Which one of the following best describes the method of reasoning used in the argument?”
* “The argument uses which one of the following methods of reasoning?”
How to Approach:
* Identify how the conclusion is supported — is it an analogy, causal reasoning, a generalization, etc.?
* Focus on the logical structure of how the argument is developed.
Do You Need to Find the Gap?
* No, this question is about understanding the reasoning process rather than finding a gap.
Common Traps to Avoid:
* Avoid choosing answers that describe the content of the argument instead of the method of reasoning.
Correct Answer Includes:
* The correct answer will describe the method or reasoning used in the argument, such as analogy, cause/effect, or generalization.
Evaluate the Argument
Question Type Overview:
Evaluate the Argument questions ask you to find the most useful piece of information to test the argument’s strength.
Stem Examples:
* “Which one of the following would be most helpful in evaluating the argument?”
* “Which one of the following would most call into question the argument?”
How to Approach:
* Understand the argument’s conclusion and identify the key assumption that makes the conclusion possible.
* Look for an answer choice that would directly challenge the assumption or show a weakness in the reasoning.
* The goal is to identify the most effective way to test the strength of the argument.
Do You Need to Find the Gap?
* Yes, you need to find a weakness or an assumption that can be tested to determine the validity of the argument.
Common Traps to Avoid:
* Avoid answers that provide irrelevant information or that support the argument’s conclusion.
* Don’t pick answers that are too broad or vague. The answer should test a specific logical flaw.
Correct Answer Includes:
* The correct answer will propose a question or statement that directly evaluates the validity of the argument’s reasoning by testing its key assumption or flaw.
Resolve the Paradox
Question Type Overview:
These questions ask you to resolve a contradiction or paradox within the argument. The goal is to find a solution that explains or reconciles seemingly contradictory information.
Stem Examples:
* “Which one of the following, if true, would most effectively resolve the apparent paradox?”
* “Which one of the following statements would best explain the discrepancy described above?”
How to Approach:
* Identify the paradox or discrepancy in the argument.
* Focus on finding an answer that reconciles or explains the conflicting statements or facts.
* Think about how two seemingly contradictory pieces of information can be true together.
Do You Need to Find the Gap?
* Yes, you need to identify the contradiction in the reasoning and find a piece of information that resolves the discrepancy.
Common Traps to Avoid:
* Avoid answers that only explain one side of the paradox. The correct answer should resolve the entire conflict.
* Don’t pick answers that introduce new contradictions or that don’t directly address the specific paradox.
Correct Answer Includes:
* The correct answer will explain or resolve the conflict between the contradictory facts or ideas, making both sides logically compatible.
Argument Evaluation (Critical Reasoning)
Question Type Overview:
These questions ask you to evaluate the quality of the argument presented. The goal is to assess the logical strength or validity of the argument.
Stem Examples:
* “Which one of the following would most strengthen the argument?”
* “Which one of the following best describes a weakness in the argument?”
How to Approach:
* Focus on the conclusion and the premises supporting it.
* Assess whether the reasoning is sound and whether the premises adequately support the conclusion.
* Look for an answer that provides evidence or reasoning that improves or diminishes the argument’s strength.
Do You Need to Find the Gap?
* Yes, you often need to identify a weakness or an unsupported assumption that would either bolster or undermine the argument.
Common Traps to Avoid:
* Avoid choosing answers that are too general or unrelated to the argument.
* Don’t pick answers that only offer tangential support without addressing the main reasoning of the argument.
Correct Answer Includes:
* The correct answer will directly improve or weaken the logical reasoning or assumptions that support the argument’s conclusion.
Parallel Flaw
Question Type Overview:
These questions ask you to find an argument that is flawed in the same way as the argument in the stimulus. You need to match the flaw in reasoning, not just the content.
Stem Examples:
* “Which one of the following contains the same flawed reasoning as the argument above?”
* “Which of the following arguments contains reasoning most similar to that in the argument above?”
How to Approach:
* Focus on the type of reasoning used in the stimulus.
* Identify the flaw in reasoning — is it a false analogy, an unwarranted assumption, etc.?
* Find the answer choice that mirrors the same logical flaw, not just the same conclusion or content.
Do You Need to Find the Gap?
* Yes, you need to identify the flawed reasoning and match it to an answer choice that demonstrates the same flaw.
Common Traps to Avoid:
* Be careful not to focus on superficial similarities in content. The key is to match the reasoning flaw, not just the surface-level details.
* Avoid answers that are only similar in reasoning but don’t follow the exact same flaw in the argument. The flaw should match in structure, not just in the general conclusion or approach.
Logical Contradiction
Question Type Overview:
These questions ask you to identify a logical contradiction within the argument, meaning there is a direct conflict between two pieces of information, or an inconsistency that undermines the argument.
Stem Examples:
* “Which one of the following would most logically resolve the contradiction above?”
* “Which of the following most directly addresses the contradiction in the argument?”
How to Approach:
* Carefully examine the contradiction presented in the stimulus.
* Look for statements or pieces of information that are in conflict with each other or that suggest the argument is logically inconsistent.
* The correct answer will either resolve the conflict or highlight the inconsistency that challenges the argument.
Do You Need to Find the Gap?
* Yes, you need to find the logical inconsistency or contradiction and identify how it impacts the argument’s validity.
Common Traps to Avoid:
* Don’t be misled by answers that restate or explain the contradiction but don’t directly address it.
* Avoid answers that offer information that introduces new contradictions instead of resolving or explaining the existing one.
Correct Answer Includes:
* The correct answer will either resolve the contradiction or show how the inconsistency undermines the argument. It should help reconcile conflicting information in a logical way.
Determine the Role of a Statement
Question Type Overview:
These questions ask you to identify the role a specific statement plays within the argument. You need to figure out whether the statement is a premise, conclusion, counterargument, or something else.
Stem Examples:
* “The statement in bold serves which of the following roles in the argument?”
* “Which of the following best describes the function of the statement in the argument?”
How to Approach:
* Understand the structure of the argument: Identify the premise, conclusion, and any other components like counterarguments or assumptions.
* Focus on the statement in question and how it fits into the overall reasoning. Does it support the conclusion, weaken the argument, or introduce a new idea?
Do You Need to Find the Gap?
* No, this question focuses on understanding the structure of the argument, not on identifying any gaps.
Common Traps to Avoid:
* Avoid choosing answers that describe the content of the statement, rather than its role in the argument.
* Be careful not to confuse evidence with conclusion — the role can often be subtle, and you’ll need to focus on how the statement is used in the reasoning.
Correct Answer Includes:
* The correct answer will clearly identify the function of the statement, such as whether it is acting as a premise, conclusion, counterargument, or supporting evidence.
Point at Issue
Question Type Overview:
Point at Issue questions ask you to identify the disagreement between two speakers or arguments. You need to pinpoint where their views diverge.
Stem Examples:
* “Which of the following is the point at issue between the two speakers?”
* “On which of the following points do the two arguments differ?”
How to Approach:
* Identify the views of both parties in the stimulus.
* Look for the specific point where they disagree or offer opposing views.
* The answer will be a statement that directly highlights the disagreement.
Do You Need to Find the Gap?
* No, this type doesn’t require you to find a gap in reasoning but rather focuses on identifying opposing views.
Common Traps to Avoid:
* Don’t confuse areas of agreement with points of disagreement.
* Be careful not to select answers that address unrelated issues or topics that don’t directly reflect the disagreement.
Correct Answer Includes:
* The correct answer will pinpoint a clear point of disagreement between the two speakers or arguments.
Assumption Sufficient or Necessary?
Question Type Overview:
These questions ask you to determine whether an assumption is sufficient or necessary for the argument to hold true. A sufficient assumption guarantees the conclusion, while a necessary assumption is essential for the argument’s logic.
Stem Examples:
* “Which one of the following is a sufficient assumption for the argument?”
* “Which one of the following is a necessary assumption for the argument?”
How to Approach:
* If the question asks for a sufficient assumption, think about which assumption, if true, would guarantee the conclusion.
* If the question asks for a necessary assumption, identify the assumption that is required for the conclusion to be logically valid.
* The goal is to determine how the assumption supports or connects the premise and conclusion.
Do You Need to Find the Gap?
* Yes, you need to identify the assumption and understand whether it is sufficient (makes the conclusion inevitable) or necessary (the argument would fall apart without it).
Common Traps to Avoid:
* Avoid confusing sufficient assumptions with necessary ones. A sufficient assumption guarantees the conclusion, while a necessary one is required for the argument to be valid.
* Don’t pick answers that introduce new facts that don’t directly support the argument’s reasoning.
Correct Answer Includes:
* For sufficient assumption questions, the correct answer will be an assumption that guarantees the conclusion.
* For necessary assumption questions, the correct answer will be an assumption that is required for the argument to make sense.
Must Be True / Inference/supported?
Question Type Overview:
These questions ask you to identify the statement that must be true based on the information provided in the stimulus. You are looking for an answer that is directly supported by the facts given — not something that requires speculation, assumptions, or outside knowledge.
Stem Examples:
“If the statements above are true, which one of the following must also be true?”
“Which one of the following can be properly inferred from the passage?”
“The statements above, if true, most strongly support which of the following?”
How to Approach:
Read the stimulus carefully and treat all the information as true.
Focus on what can be proven directly — stick to what is explicitly stated or logically follows.
Avoid bringing in any outside information or opinions.
Often, the correct answer will restate or combine facts from the stimulus in a new way.
Do You Need to Find the Gap?
No, these are not assumption-based arguments. There is no “gap” to fill — you’re not evaluating reasoning flaws or missing links.
Your job is to identify what follows logically and unavoidably from the text.
Common Traps to Avoid:
Answers that go too far — something that is possible but not guaranteed.
Answers that make comparisons or assumptions not explicitly mentioned.
Answers that twist or exaggerate the stimulus information.
Tempting answers that are true in the real world, but not provable from the passage alone.
Correct Answer Includes:
A statement that can’t be denied if the stimulus is true.
It will be a direct restatement, logical combination, or undeniable consequence of the facts provided.
Sometimes, the correct answer is subtle — a small, precise inference rather than a bold or sweeping conclusion.
Justify the Conclusion
Question Type Overview:
These questions ask you to find the answer choice that proves the argument’s conclusion is logically valid. The correct answer will bridge the gap between the premises and the conclusion, making the reasoning airtight.
Stem Examples:
“Which one of the following, if assumed, allows the conclusion to be properly drawn?”
“The conclusion follows logically if which one of the following is assumed?”
“Which of the following is sufficient to justify the argument’s conclusion?”
How to Approach:
Identify the premises and the conclusion.
Look for the gap — what is missing that would fully connect the premises to the conclusion?
The correct answer guarantees the conclusion based on the premises.
Use the Mechanistic Approach: Any new element in the conclusion must appear in the correct answer, and any new element in the premises must be used in the correct answer.
Do You Need to Find the Gap?
Yes! This is all about filling the gap between premises and conclusion.
Common Traps to Avoid:
Answers that strengthen the argument but don’t fully guarantee the conclusion.
Answers that are true, but are not required to make the argument valid.
Answers that introduce new information irrelevant to the argument.
Correct Answer Includes:
A strong, definitive connection between the premises and the conclusion.
Language that directly ties any new terms or concepts in the conclusion to the premises.
It forces the conclusion to follow logically if the premises are true.
Principle
Principle-Strengthen or Principle-Support questions ask you to choose a general rule or principle that, if assumed to be true, strengthens the argument in the stimulus. These questions require you to bridge the gap between the evidence and the conclusion using a general principle.
How to identify:
These questions usually include phrasing like:
• “Which one of the following principles, if valid, most helps to justify the reasoning in the argument above?”
• “The conclusion above follows logically if which one of the following principles is assumed?”
• “Which one of the following most justifies the reasoning in the argument?”
How to solve:
Start by identifying the conclusion of the argument and then the supporting evidence. Next, look for the logical gap—the assumption the argument relies on to move from evidence to conclusion. Your goal is to find a principle that, if true, justifies that move. The correct principle will function as a rule that makes the reasoning logically valid or at least more persuasive.
Gap:
These arguments often rely on an unstated assumption. The gap is the missing link between the evidence and conclusion. For example, if the argument concludes that someone is morally wrong for doing something, but the evidence only shows that they broke a promise, the missing assumption might be that breaking promises is morally wrong. The correct principle would generalize this connection.
Common traps to avoid:
1. Irrelevant principles: Some answer choices may state valid principles that don’t apply to the argument at all.
2. Too weak or too strong: A principle that is too narrow may not cover the situation in the argument, while one that is too broad might include irrelevant scenarios.
3. Backward principles: Some choices may reverse the logic, stating what would follow if the conclusion were true, instead of supporting why the conclusion follows from the evidence.
4. Restatements: Choices that simply restate the conclusion or evidence without providing a connecting principle.
Correct answer includes:
• A general rule or principle that, if accepted as true, makes the conclusion follow more logically from the evidence
• A statement that covers both the evidence and the conclusion
• A justification for the reasoning used in the argument
The correct answer often looks like a general moral, legal, or causal rule that plugs the logical gap and supports the argument’s reasoning.
