GMAT · Argument structure, explanations and plans · TOPIC LESSON
Argument roles, reasoning patterns and explanations
Map who supports what, recognize valid moves and explain apparent contradictions without erasing facts.
GMAT45 min study guide9 indexed sections
BY THE END, YOU CAN
Explain and apply identify argument role
Explain and apply boldface-style role reasoning as editorial extension
Explain and apply reasoning method
Explain and apply logical flaws
Explain and apply valid versus invalid conditional inference
Explain and apply resolve apparent paradoxes
Explain and apply competing explanations
BEFORE YOU START
Read an argument or passage without assuming that every speaker agrees.
Distinguish a claim from the evidence offered for it; interpret simple counts and percentages.
Original educational lesson. Work through the examples before revealing the practice answers. This original lesson supports current GMAT study through an editorial skill map. It does not reproduce official questions, predict exam content or guarantee a score.
LEARN THROUGH ORIGINAL PRACTICE
Original GMAT-style worked examples and practice
All passages, examples and exercises here are original. No official GMAC questions, choices or explanations are reproduced. This independent preparation resource is not affiliated with or endorsed by GMAC. GMAT is a trademark of the Graduate Management Admission Council.
01 / UNDERSTAND & APPLY
Argument roles are relations
A statement’s role depends on how the author uses it: premise, intermediate conclusion, main conclusion, counterclaim, objection, concession or background. First separate voices, then draw support and opposition links. A forcefully phrased sentence is not automatically the main conclusion.
Role questions can refer to highlighted statements. In this lesson, labeled-sentence or boldface-style analysis is an editorial teaching extension for practicing argument structure; it is not a claim about an official current item category or frequency. The same role skills help you understand ordinary Critical Reasoning arguments.
ORIGINAL WORKED EXAMPLE
Two labeled claims
A residents’ group argues: “[1] Removing the old footbridge would reduce maintenance costs. But it is the only step-free river crossing within two kilometers. [2] The council should repair it rather than remove it.” What roles do [1] and [2] play?
[1] supplies a consideration favoring the option the group ultimately rejects. It is a concession, not the author’s final recommendation.
The accessibility premise supports [2], which states the group’s main recommendation.
The argument does not deny all maintenance savings; it judges another consideration more important.
Answer [1] is a conceded benefit of the rejected option; [2] is the main conclusion.
02 / UNDERSTAND & APPLY
Reasoning methods: describe the move
An argument may use an analogy, eliminate alternatives, infer a cause, generalize from a sample, apply a principle or compare costs and benefits. Describe what the argument does, not merely what it is about. “Discusses a bridge” is a subject; “accepts a cost benefit but argues it is outweighed by accessibility” is a method.
A method description must fit the actual support. Do not call an argument deductive merely because it uses numbers, or analogical merely because it mentions two cases. Ask whether the conclusion follows from a general rule, a comparison, an observed pattern or a proposed explanation.
ORIGINAL WORKED EXAMPLE
Identify the method
A retailer says: “Our return policy worked for low-cost stationery. High-cost equipment, however, has different repair and resale costs, so we should not assume the same policy will be profitable for equipment.” Describe the method.
The speaker identifies a relevant difference between the original and proposed application.
The difference concerns the mechanism determining profit, not a superficial product label.
The conclusion rejects an unearned transfer; it does not prove the equipment policy must fail.
Answer It challenges an analogy by identifying a difference relevant to the predicted outcome.
03 / UNDERSTAND & APPLY
Logical flaws: identify the exact gap
Common flaws include treating a necessary condition as sufficient, assuming a correlation is causal, generalizing from a biased sample, changing denominators, shifting a term’s meaning and inferring an individual property from a group average. Name the gap and show a counterexample when possible.
A flaw diagnosis is more useful than a slogan. “The sample is small” is not always the best objection; a large but self-selected sample can be more misleading. Explain which conclusion the evidence fails to establish and why.
ORIGINAL WORKED EXAMPLE
Group average versus individual fact
The average delivery time for Service A is shorter than for Service B. A customer concludes that every A delivery is faster than every B delivery. Diagnose.
Averages do not establish complete separation between individual observations.
A can have times of 1 and 9 hours, average 5; B can have 6 and 6 hours, average 6.
A has the lower average, yet its 9-hour delivery is slower than B’s 6-hour deliveries.
Answer The argument improperly converts a group-average comparison into a universal individual comparison.
04 / UNDERSTAND & APPLY
Valid and invalid conditional patterns
For P → Q, modus ponens is P, therefore Q. Modus tollens is not Q, therefore not P. Affirming the consequent is Q, therefore P; denying the antecedent is not P, therefore not Q. The latter two are invalid without further premises.
A chain P → Q and Q → R yields P → R. Do not reverse the chain. Keep scope restrictions: a rule about this year’s applicants does not automatically cover earlier applicants. Negation of a conjunction or disjunction also needs care: not both P and Q means at least one is false, not necessarily both.
ORIGINAL WORKED EXAMPLE
Four arguments, one rule
Rule: If a device is in secure mode, remote access is disabled. Evaluate: (a) secure mode, so remote access disabled; (b) remote access enabled, so not secure mode; (c) remote access disabled, so secure mode; (d) not secure mode, so remote access enabled.
(a) follows directly by modus ponens.
(b) is the contrapositive, treating enabled as the stated opposite of disabled in this two-state access setting.
(c) fails because remote access may be disabled for another reason. (d) fails because leaving secure mode need not enable remote access.
Answer (a) and (b) are valid; (c) and (d) are invalid.
05 / UNDERSTAND & APPLY
Resolve an apparent paradox by adding a compatible fact
A paradox question presents two facts that seem difficult to reconcile. Accept both and seek a third fact that makes them coexist naturally. Do not “resolve” the puzzle by denying one of the facts. Useful distinctions include totals versus rates, new versus existing users, short versus long time horizons, different groups and offsetting effects.
State why the added fact affects both sides. An irrelevant detail may be true but leave the tension untouched. A successful explanation need not be the only imaginable explanation; it should be the best of the offered choices.
ORIGINAL WORKED EXAMPLE
More visitors, lower revenue
A gallery cut its admission price in half. Paid attendance rose by 40%, yet admission revenue fell. Is this inconsistent? Explain with an original numerical case.
Start with a $10 ticket and 100 paid visitors: revenue is $1,000.
After the cut, $5×140 visitors=$700.
The 40% volume increase is too small to offset a 50% price reduction. Both reported facts can hold.
Answer No inconsistency: admission revenue can fall from $1,000 to $700 despite higher paid attendance.
06 / UNDERSTAND & APPLY
Compare explanations by discriminating evidence
Two explanations can fit the same observed fact. To distinguish them, seek a prediction on which they differ. If delayed shipments might reflect either insufficient staff or a late supplier, evidence about when goods reached the warehouse is more discriminating than the observation that shipments were late.
An explanation that merely repeats the outcome is not informative. “Sales fell because fewer products were sold” may restate the phenomenon; an explanation should supply a mechanism or relevant distinction. Prefer evidence that changes the relative support for the proposed explanations.
ORIGINAL WORKED EXAMPLE
A discriminating observation
Warehouse delays might arise from too few packers or from suppliers delivering goods late. Which observation best distinguishes these accounts: the warehouse wall color, or whether goods were already present and waiting before scheduled packing began?
If goods were present but waited, packing capacity becomes more plausible.
If goods arrived after the packing window, supplier timing becomes more plausible.
Wall color has no stated link to either explanation.
Answer Whether the goods were present before scheduled packing began.
07 / UNDERSTAND & APPLY
A practical role-and-method procedure
Read the whole argument once. Label the author’s conclusion, then identify the evidence and any rival view. For a highlighted statement, ask both “Who asserts this?” and “Does the author use it, oppose it or concede it?” For method questions, replace topic nouns with role labels and preserve the inference.
For flaw or paradox items, a quick counterexample can reveal the structure. Keep it consistent with every premise. Do not use outside facts that contradict the stipulated scenario merely because they are realistic.
08 / UNDERSTAND & APPLY
Practice: role and conditional reasoning
Give the requested role, method or validity judgment.
ORIGINAL PRACTICE · 1
1. “Some critics say the park should close because maintenance is expensive. Yet it is the only nearby play space, so the city should fund repairs.” What role does the critics’ proposal play?
Reveal answer & reasoning
It is an opposing conclusion the author rejects.
The author reports the closure position before giving accessibility-based support for repairs. Reporting is not endorsement.
ORIGINAL PRACTICE · 2
2. “Every licensed guide passed the exam. Noor did not pass.” What follows?
Reveal answer & reasoning
Noor is not a licensed guide under the rule.
This is modus tollens: licensed → passed; not passed → not licensed. It does not show what other work Noor may do.
ORIGINAL PRACTICE · 3
3. “Every licensed guide passed the exam. Noor passed, so Noor is licensed.” Valid?
Reveal answer & reasoning
No; it affirms the consequent.
Other people may have passed without completing all licensing requirements. The premise gives only one direction.
ORIGINAL PRACTICE · 4
4. “If a form is accepted, it is complete. This form is not accepted, so it is incomplete.” Valid?
Reveal answer & reasoning
No; it denies the antecedent.
A complete form might be rejected for a different reason. Nonacceptance does not establish incompleteness.
ORIGINAL PRACTICE · 5
5. An argument notes two firms sell similar products and infers they will respond identically to a tax, ignoring that one imports and one manufactures locally. What is the flaw?
Reveal answer & reasoning
It relies on an analogy while ignoring a difference relevant to tax exposure.
Product similarity alone does not make the tax mechanism the same. The criticism identifies a relevant difference rather than rejecting all analogies.
ORIGINAL PRACTICE · 6
6. A company’s revenue rises while profit falls. Give a compatible explanation.
Reveal answer & reasoning
Costs rose by more than revenue.
For example, revenue rises from $100 to $120 while costs rise from $70 to $100; profit falls from $30 to $20. Neither reported fact is denied.
09 / UNDERSTAND & APPLY
Practice: distinguish the explanations
Choose the information that changes the logical assessment.
ORIGINAL PRACTICE · 1
7. A recycling center receives more material but recovers less usable paper. Which best resolves this? A: A much larger share of incoming material is contaminated. B: The building is old. C: Employees have uniforms. D: The sign is green. E: The manager reads newspapers.
Reveal answer & reasoning
A
More incoming volume can yield less usable output if the usable fraction falls enough. B through E do not connect the two quantities without extra assumptions.
ORIGINAL PRACTICE · 2
8. Two accounts explain lower museum attendance: reduced tourist arrivals or an unpopular new exhibit. Why would attendance at comparable museums without the exhibit be useful?
Reveal answer & reasoning
It helps separate a general tourism change from an exhibit-specific effect.
A similar decline elsewhere supports the broader tourism account; stable attendance elsewhere makes an exhibit-specific account more plausible. The comparison is evidence, not conclusive proof.
KEEP THE BIG IDEAS
Quick revision
Label statement roles relative to the author’s conclusion and voice.
Valid conditional moves preserve direction or use the contrapositive.
Resolve a paradox by reconciling facts, not denying them.
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