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Strip away topic while preserving logical direction, quantities, negation and the relation between premises and conclusion.
Paper packet. Every task here also exists on screen, where it is checked automatically; answers written on paper are not assessed by Nydus. When you are back at a device, enter your answers there.
Recognize an argument with the same reasoning structure, including the same defect when the task asks for a parallel flaw.
The flaw lesson named unsupported transitions and the inference lesson followed valid ones. Parallel questions ask you to recognize the same transition in another setting. The surface topic can change completely while the support structure stays the same.
| Term | What it means |
|---|---|
| Logical form | The arrangement of claims and inferential connections independent of their particular subject matter. |
| Contraposition | Using not B to infer not A from if A then B. |
| Converse error | Inferring A from B when only A implies B is stated. |
| Parallel flaw | The same unsupported inferential move in a different argument. |
A parallel-reasoning task asks for an argument whose premises support its conclusion in the same way as the original. A parallel-flaw task asks for an argument that makes the same kind of reasoning error. In either case, matching the topic is insufficient. Two arguments about museums may have different structures, while an argument about tickets may match one about insulated containers exactly.
Reduce the original to a small map. Every A is B; this object is not B; therefore it is not A is a valid contrapositive pattern. Every A is B; this object is B; therefore it is A is an invalid converse pattern. The words all, some, not and therefore do essential work. Removing them in a summary removes the very structure you need to compare.
Write or mentally track the conclusion separately. An option can contain the same premises but draw a different conclusion. Another can use the same conclusion wording but different support. The match must preserve the inferential relationship, including whether the conclusion is universal, existential, conditional, negative or merely probable.
Another way: picture
Replace content terms with boxes labeled A, B and C. Keep arrows, overlap and negation visible. A candidate matches when its boxes can be relabeled without changing the connections.
Another way: steps
Locate the conclusion; summarize the premise pattern; preserve quantity and negation; compare each candidate's conclusion and support; reject matches that share only a topic or vocabulary.
The conclusion is not always the final sentence. Use the offered support direction to identify it, then map the remaining claims as premises. If you accidentally treat an intermediate conclusion as the final conclusion, your abstract pattern can omit a whole inferential step.
A candidate may place its conclusion first and still match. Sentence order and logical order are different. Reorganize both arguments into premises followed by conclusion before comparing them. You are not matching the number of commas or the location of an indicator word. You are matching what is being offered as support for what.
The four common conditional patterns are easy to confuse because they use the same two categories. From A implies B, A to B is valid and not B to not A is valid. B to A and not A to not B are not guaranteed. Label the supplied fact before deciding which pattern you have.
Negation can be expressed without the word not. Lacks a badge can function as not having a badge; excluded from entry can be the negative of being permitted entry in the stated system. Translate meaning, not just visible words. At the same time, avoid treating unrelated opposites as exact negations when the passage leaves intermediate possibilities.
Some A are B followed by every B is C supports some A are C. Replacing the second premise with some B are C destroys the guarantee because the two existential groups may not overlap. Replacing the conclusion with all A are C also changes the inference. These are not minor wording differences.
A universal chain, every A is B and every B is C, supports every A is C. It does not by itself prove that any A exists. When matching, check whether a named example or an existential premise is present. A candidate that adds existence can differ in the precise route to its conclusion even if the categories look similar.
Two invalid arguments need not be parallel. One may reverse a conditional while another generalizes from an unrepresentative sample. Saying both are bad reasoning is too broad. Name the unsupported move and check that the candidate repeats it.
For a composition error, the relevant feature is transfer of a property from parts to a combined whole without justification. The parts need not be physical objects, but the property must be one whose combination matters in the same way. An argument about individual low prices and total cost can parallel one about individual light objects and total weight. An unrelated attack on a speaker's motives cannot.
A matching argument can have strange or false premises. The task often asks about form rather than real-world truth. If all fictional creatures of one kind have a feature and a named creature lacks it, the conditional pattern can still match a familiar argument about registration. Accept the stipulated premises for comparison.
Conversely, a conclusion that happens to be true does not repair a mismatched inference. If someone with a ticket happens to be a passenger, that fact does not make the general ticket-to-passenger converse valid. The question is what the supplied premises establish, not what an outside observer knows about the particular person.
First compare conclusion type. A universal negative conclusion is unlikely to match an existential positive one. Then compare the major relation: implication, disjunction, quantified overlap, analogy or a causal inference. Finally check the exact direction and any missing condition. This order reduces unnecessary rereading without substituting a superficial shortcut.
When two options remain, construct a compact description of each. If one says A implies B, not B, therefore not A, and the other says A implies B, not A, therefore not B, their shared negative wording no longer disguises the difference. A complete comparison should explain both why the correct candidate matches and which single structural change defeats the closest rival.
A policy discussion, a scientific report and an everyday explanation can use the same inferential pattern. Recognizing the pattern lets you transfer a reasoning check without importing the original topic's facts. For example, the difference between a requirement and a sufficient condition matters in both scheduling policies and equipment specifications.
The exercises automatically grade matches among supplied arguments. They do not establish that a learner can invent every possible parallel or produce a formal proof. When reviewing an error, replace the nouns with category letters and preserve the connecting words. Then identify the exact point where the wrong candidate changes the pattern. On a later attempt, try reading the conclusion before the subject matter. This helps keep vivid stories from distracting you from the structural relation the question actually asks you to compare.
Keep quantity, direction, negation and conclusion type. A parallel-flaw question needs the same defect, not any invalid argument, and a valid parallel need not use believable real-world premises. When a candidate changes only one logical connector, that small wording change can still destroy the match; compare the inferential relation rather than the amount of shared language.
Read the passage and question.
Every insulated container retains heat. This container does not retain heat. Therefore it is not insulated.
Which argument has the same valid reasoning pattern?
Retain the absence of the consequent as the premise.
Compare the five proposed answers.
1: Every registered entrant has a badge. Ana has no badge, so Ana is not a registered entrant. 2: Every registered entrant has a badge. Ana has a badge, so Ana is registered. 3: Every registered entrant has a badge. Ana is not registered, so Ana has no badge. 4: Some entrants have badges, so every entrant has a badge. 5: Ana wears a badge because badges look attractive.
Apply the question's test to each option; do not choose solely by shared vocabulary.
Explain the best answer.
Every registered entrant has a badge. Ana has no badge, so Ana is not a registered entrant.
Both use if A then B, not B, therefore not A.
Account for every rejected answer.
2: This affirms the consequent instead of using contraposition. 3: This denies the antecedent. 4: This changes quantity from some to all. 5: This is an explanation of behavior, not the same deduction.
Each rejection identifies a specific mismatch with the passage or task.
Read the passage and question.
Some musicians are gardeners. Every gardener owns gloves. Therefore some musicians own gloves.
Which argument most closely parallels the reasoning?
The some premise supplies a witness and the all rule carries that same witness forward.
Compare the five proposed answers.
1: Some runners are volunteers. Every volunteer has a pass. Therefore some runners have passes. 2: All runners volunteer, and some volunteers have passes, so all runners have passes. 3: Some runners volunteer and some volunteers have passes, so some runners have passes. 4: Every runner has a pass, so every pass holder runs. 5: No runners volunteer, so some runners volunteer.
Apply the question's test to each option; do not choose solely by shared vocabulary.
Explain the best answer.
Some runners are volunteers. Every volunteer has a pass. Therefore some runners have passes.
The same existential witness moves through a universal rule.
Account for every rejected answer.
2: The quantities and overlap differ. 3: Two existential groups need not overlap. 4: This reverses a universal rule. 5: This contradicts rather than follows the premise.
Each rejection identifies a specific mismatch with the passage or task.
Read the passage and question.
Every approved device has a label. Device F has a label, so it must be approved.
Which argument contains the same flaw?
This time the task asks for the same flaw, so a valid inference is not the match.
Compare the five proposed answers.
1: Every trained pilot passed an exam. Jae passed the exam, so Jae must be a trained pilot. 2: Every trained pilot passed an exam. Jae did not pass, so Jae is not a trained pilot. 3: Every trained pilot passed an exam. Jae is a trained pilot, so Jae passed. 4: Some pilots passed an exam, so some exam passers are pilots. 5: No pilot is on duty, so this on-duty worker is not a pilot.
Apply the question's test to each option; do not choose solely by shared vocabulary.
Explain the best answer.
Every trained pilot passed an exam. Jae passed the exam, so Jae must be a trained pilot.
Both wrongly infer A from B after stating A implies B.
Account for every rejected answer.
2: That is valid contraposition. 3: That follows the rule forward. 4: That preserves an existing overlap. 5: That is a valid exclusion rather than the same flaw.
Each rejection identifies a specific mismatch with the passage or task.
Check the difficult boundary.
The correct parallel repeats the error; selecting it does not endorse its conclusion as proved.
This last check preserves the exact strength and scope of the answer rather than turning it into a broader claim.
Map the original alternatives.
The file is in Cabinet A or B, and it is not in A, so it is in B.
At least one alternative must hold.
Supply a parallel argument.
The session is online or in person; it is not online, so it is in person.
The candidate excludes one disjunct while preserving the exhaustive either-or premise.
Reject the near match.
If a parcel is express, it is tracked. If it is tracked, its location is recorded. Therefore every express parcel has a recorded location. Which argument matches the pattern?
Every object in cabinet R is catalogued. Some brass objects are in cabinet R. Therefore some brass objects are catalogued. Which argument has the same valid pattern? (1) Every cedar is tagged. Some tall trees are tagged. Therefore some tall trees are cedars. (2) Some cedars are tagged. Every tall tree is a cedar. Therefore every tall tree is tagged. (3) No cedars are tagged. Some tall trees are cedars. Therefore some tall trees are not tagged. (4) Every cedar is tagged. Therefore some cedars are tagged. (5) Every cedar in the grove is tagged. Some tall trees are cedars in the grove. Therefore some tall trees are tagged. Abstract the premise-to-conclusion pattern, preserving direction, negation and quantity before matching a new topic. Complete the method with the number of the best answer.
Name the precise task.
Abstract the premise-to-conclusion pattern, preserving direction, negation and quantity before matching a new topic.
The question determines what would count as a successful answer.
Compare the candidates against the target.
Best answer: answer.
Preserve quantities, speaker attribution and the exact conclusion or passage claim.
Check the strongest rival.
Explain which required connection that rival lacks.
A defensible rejection exposes the misconception rather than memorizing an option number.
Every passenger has a ticket. Rui is not a passenger, so Rui has no ticket. Which argument repeats the same flaw? (1) Every sculptor owns tools. Elin owns no tools, so Elin is not a sculptor. (2) Every sculptor owns tools. Elin is a sculptor, so Elin owns tools. (3) Some sculptors own tools, so some tool owners are sculptors. (4) Elin owns either a saw or a drill, not a saw, so a drill. (5) Every sculptor owns tools. Elin is not a sculptor, so Elin owns no tools. Enter Y for the best answer to the question and N for each rejected alternative. Then identify the question kind. Task codes: AR argument parts; NA necessary assumption; SA sufficient assumption; ST strengthen; WE weaken; FL flaw; IN inference; PR principle; PA parallel; RE resolve; ME method or role; DI disagreement; EV evaluate; AN analogy; MU misunderstanding; MP main point or structure; DE detail or supported reading inference; CO compare passages; AT attitude or application; VC words and rhetorical purpose; RP passage principles and analogies; NE new evidence in reading; WR writing-plan analysis. These analysis records are instructional exercises, not the official response format.
| Analysis | Y/N or task code |
|---|---|
| Alternative 1 | |
| Alternative 2 | |
| Alternative 3 | |
| Alternative 4 | |
| Alternative 5 | |
| Question kind |
If a parcel is express, it is tracked. If it is tracked, its location is recorded. Therefore every express parcel has a recorded location. Which argument matches the pattern?
Every passenger has a ticket. Rui is not a passenger, so Rui has no ticket. Which argument repeats the same flaw?
Every object in cabinet R is catalogued. Some brass objects are in cabinet R. Therefore some brass objects are catalogued. Which argument has the same valid pattern?
If a film is selected, it is screened. This film is selected. Therefore it is screened. Which argument has the same pattern?
Every instrument in the case is tuned. Flute F is not tuned. Therefore F is not in the case. Which argument matches the reasoning?
Some painters are hikers. Some hikers are teachers. Therefore some painters are teachers. Which argument repeats the flaw?
Unless a parcel is tagged, it remains in storage. This parcel did not remain in storage. Therefore it was tagged. Which argument matches this pattern?
Each member of the relay team is fast. Therefore the team must complete the exchange of the baton without delay. Which argument makes the most similar mistake?
Either the package is in Locker A or it is in Locker B. It is not in A. Therefore it is in B. Which argument has the same pattern? (1) If Monday then Tuesday; Monday, so Tuesday. (2) Some meetings are on Tuesday, so this one is. (3) The meeting is Monday or Tuesday; Monday, so not Tuesday. (4) The meeting is not Monday, so no meetings occur. (5) The meeting is on Monday or Tuesday; it is not Monday, so it is Tuesday. Enter Y for the best answer to the question and N for each rejected alternative. Then identify the question kind. Task codes: AR argument parts; NA necessary assumption; SA sufficient assumption; ST strengthen; WE weaken; FL flaw; IN inference; PR principle; PA parallel; RE resolve; ME method or role; DI disagreement; EV evaluate; AN analogy; MU misunderstanding; MP main point or structure; DE detail or supported reading inference; CO compare passages; AT attitude or application; VC words and rhetorical purpose; RP passage principles and analogies; NE new evidence in reading; WR writing-plan analysis. These analysis records are instructional exercises, not the official response format.
| Analysis | Y/N or task code |
|---|---|
| Alternative 1 | |
| Alternative 2 | |
| Alternative 3 | |
| Alternative 4 | |
| Alternative 5 | |
| Question kind |
Lesson test: one question per skill, one attempt each, no hints. Your answers are checked when you submit.
Every piece in a sculpture is light enough for one person to carry. Therefore the whole sculpture is light enough for one person to carry. Which argument makes the same kind of mistake? (1) Every metal item conducts electricity, and this is metal, so it conducts. (2) No frozen item is warm; this is frozen, so it is not warm. (3) Some artists teach, so some teachers are artists. (4) If a shop opens then staff arrive; it opens, so staff arrive. (5) Every item on the shopping list is cheap, so buying every item together must be cheap. Enter Y for the best answer to the question and N for each rejected alternative. Then identify the question kind. Task codes: AR argument parts; NA necessary assumption; SA sufficient assumption; ST strengthen; WE weaken; FL flaw; IN inference; PR principle; PA parallel; RE resolve; ME method or role; DI disagreement; EV evaluate; AN analogy; MU misunderstanding; MP main point or structure; DE detail or supported reading inference; CO compare passages; AT attitude or application; VC words and rhetorical purpose; RP passage principles and analogies; NE new evidence in reading; WR writing-plan analysis. These analysis records are instructional exercises, not the official response format.
| Analysis | Y/N or task code |
|---|---|
| Alternative 1 | |
| Alternative 2 | |
| Alternative 3 | |
| Alternative 4 | |
| Alternative 5 | |
| Question kind |
Tomorrow, reconstruct one valid contrapositive and one invalid converse using new subject matter. Preserve some, all and not. Next: explain how two surprising observations can both be true.
16. A disjunction in a new setting, step 3
Online or in person, online, therefore not in person requires an exclusive-or premise not stated here.
Inclusive or allows both alternatives.