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Separate logical requirements from causal evidence, then choose the method the question actually requires.
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.
Separate logical requirements from causal evidence, then choose the method the question actually requires.
Separate logical requirements from causal evidence, then choose the method the question actually requires.
| Term | What it means |
|---|---|
| Contrapositive | The equivalent rule obtained by reversing an implication and negating both parts. |
| Counterexample | A possible case satisfying the premises while defeating the proposed conclusion. |
| Necessary assumption | A condition the offered reasoning needs, even if it does not prove the conclusion. |
| Confounder | A factor that can help account for an observed association apart from the proposed cause. |
A difficult argument often contains several claims that play different roles. One sentence states an observation, another interprets it, and a third recommends an action. Mark these roles before deciding whether the conclusion sounds reasonable. A conclusion can be true while the offered support remains inadequate. Conversely, an unfamiliar conclusion may follow from premises you are asked to accept. Your task is to evaluate the relationship specified by the question, not to vote for a policy you already favor. Keep background knowledge from silently supplying a missing bridge. When a passage reports an expert's view, distinguish that reported view from the current author's endorsement or criticism of it.
Another way: steps
Permit implies review and insurance. Review implies signed record. Follow the arrows from permit to signed record; do not turn the arrows around. For a causal claim, instead compare intervention, alternative change and recorded outcome. Select the map that matches the question's burden.
Translate a requirement in the direction that preserves its force. A grant only if a review occurs means grant implies review. It does not mean review guarantees a grant. When two requirements appear together, acceptance implies both; learning that one is satisfied leaves the other unresolved. The contrapositive preserves the original claim: no review implies no grant. Inverting it does not: no grant need not imply no review. A chain can connect several requirements, but every link must point in the direction you use. Draw a counterexample to a tempting reversal by allowing an applicant to meet a requirement while failing another undisclosed requirement. This demonstrates the gap more clearly than memorizing a label.
Some statements introduce at least one case, not a typical case or a majority. If some reports are anonymous and all anonymous reports are verified, at least one report is verified. You have followed the same witness through a universal rule. If some reports are anonymous and some reports are urgent, however, the two groups need not overlap. Invent two reports, one anonymous but not urgent and another urgent but not anonymous. Both premises hold without a report that has both properties. This small model defeats the unsupported conclusion. Do not add existence to a universal statement alone: all approved projects are insured does not establish that any approved project exists.
When an outcome changes after a policy, list at least three competing structures before selecting an answer. The policy might cause the outcome; another simultaneous change might cause both; or the way outcomes are measured might have changed. Selection into a treatment group adds another possibility. A successful volunteer group may have differed before the intervention. A weakening answer need not prove that the proposed cause had no effect. It only needs to damage the offered inference. A strengthening answer likewise need not establish certainty. Prefer evidence that discriminates between competing accounts over an impressive fact that both accounts equally predict. Ask what would have happened without the intervention, even when that counterfactual cannot be observed directly.
Must-follow questions demand a conclusion true in every allowed case. A single coherent counterexample defeats an option. Strengthen and weaken questions instead compare how additional evidence changes support. Necessary-assumption questions ask for a condition whose failure damages the argument, not a condition that would prove the conclusion by itself. Evaluate questions ask for a useful uncertainty: compare the implications of sharply contrasting answers. If both answers leave the inference equally supported, the question is not diagnostic. A resolve question preserves both reported facts and seeks circumstances under which they coexist. Counts and proportions frequently provide such a reconciliation because their denominators can change.
Most is stronger than some; must is stronger than may; all causes is stronger than one plausible cause. Eliminate an option that crosses these boundaries even if its topic matches perfectly. With plans, distinguish permission, necessity and success. Being allowed to use a procedure does not make its use mandatory, and satisfying one prerequisite does not establish that a plan will achieve its goal. Compare an argument's target population and time period with those named in each answer. An answer about a different group may be true but irrelevant. After choosing, state the shortest chain that supports your choice and the exact extra premise the closest rival would require. This final contrast is a better check than rereading every sentence without a purpose.
The negation test is useful only if the negation is accurate. The denial of all inspected sites are safe is that at least one inspected site is unsafe. It is not that every inspected site is unsafe. The denial of some submitted reports are reliable is that none of the submitted reports are reliable. For an argument requiring a particular bridge, negate that bridge and ask whether the offered support still reaches the conclusion. Suppose a director predicts that opening an evening office will increase completed applications because workers cannot attend during the day. A necessary assumption might be that at least some of those workers could attend in the evening. Its denial removes the very group supposed to benefit. An answer saying every worker prefers evenings would be unnecessarily strong. The argument can survive exceptions, so that stronger statement need not be required. Keep the test focused on the reasoning actually offered: an unsupported alternative reason why the conclusion might still happen does not repair the broken bridge.
Parallel reasoning requires a match between inferential structures. Replace subject labels with simple symbols only after recording the force of each statement. If the original says every approved device is tested, this device is tested, therefore it is approved, the error is reversing a necessary condition. A parallel argument must make that same reversal; merely discussing a test is irrelevant. Compare whether the premises are universal or existential, whether the conclusion is certain or probable, and whether the argument affirms or denies the relevant property. A valid contrapositive may use identical vocabulary yet have the opposite logical status. When two options remain, build a possible world for each. For the invalid reversal, a tested device that fails another approval requirement satisfies both premises and defeats the conclusion. If the rival option cannot be defeated without contradicting its own premise, it is probably not parallel to the flawed original. This check is more reliable than matching the order of sentences.
Suppose attendance increased after a museum reduced admission prices. At the same time, a new transit stop opened beside the entrance. The second change creates an alternative explanation; it does not establish that fares had no influence. A useful evaluation asks about attendance at comparable museums with unchanged prices but improved transit. If attendance rose there too, the transit account gains support; if it did not, that account loses some support. Neither answer automatically isolates every cause because the museums might differ in other ways. Evaluate the direction of the evidential change before demanding experimental certainty. Also distinguish a rival cause from an enabling condition. Visitors may need transport to benefit from cheaper tickets, so transport and price can jointly matter. A distractor that merely notes another necessary condition need not undermine a causal claim. Identify whether the answer changes the comparison, challenges the measurement, or supplies an independently plausible route to the outcome.
When reviewing errors, write the inference you actually made, not simply the official answer you missed. For a reversed condition, build one counterexample satisfying the original rule. For a causal error, identify the competing account your chosen answer failed to distinguish. For an existential error, label the possible witnesses separately. Then solve a different problem of the same structure after a delay. A remembered letter is not evidence that you can now preserve direction, identity and scope. In a timed mixed set, the aim is to make this diagnosis rapidly enough that you do not spend a must-follow question hunting for the most persuasive policy argument.
For example, a library reports 120 visits before extending hours and 150 afterward. The increase is 30 visits, but it does not identify a cause. If a neighboring branch closed in the same period, displaced visitors supply a rival explanation. Comparing the share of new visitors who formerly used that branch helps distinguish the accounts. Even if all 30 additional visits came from that group, longer hours might still have helped retain existing visitors. The defensible conclusion concerns what these counts establish, not every possible benefit of the policy.
Translate the rule
A permit requires review and insurance; review requires a signed record. Project Cedar has a permit.
Requirements run from the granted permit toward what must accompany it, not from any one prerequisite toward approval.
Carry the same project through the chain
Cedar has review and insurance; its review implies a signed record.
All consequences concern Cedar. No step substitutes a different project or treats an existential claim as a universal rule.
Reject a reversed inference
A signed record alone does not establish that another project has a permit.
That other project might lack insurance or fail a condition the rule does not describe. The record is not a complete approval rule.
State the supported result
Cedar has insurance and a signed record.
Both properties follow from explicit links. No claim about uniqueness, speed of approval or the quality of the project is needed.
Separate observation and interpretation
A depot introduced training in May; recorded incidents then fell. The director attributes the whole decline to training.
The observation concerns recorded incidents. The interpretation adds a causal claim and assigns the full effect to one intervention.
Name an alternative mechanism
In May the depot also stopped accepting anonymous incident reports.
The new procedure might suppress reporting while actual incidents remain unchanged. The alternative concerns measurement, not necessarily the occurrence of harm.
Choose discriminating evidence
Employees say they withheld reports of minor incidents because names were now required.
This supports a specific route from the procedural change to fewer records and therefore weakens attribution of the entire decline to training.
Limit the conclusion
The recorded decline alone cannot establish the full safety benefit claimed.
Training may still help. The evidence does not justify claiming that training was useless, harmful, or incapable of reducing any actual incident.
Check the measurement
Separate actual incidents from recorded reports before estimating any change in safety.
A policy affecting reporting can change the observed count without producing the same change in the underlying event rate.
Identify the witness
Some coastal surveys are anonymous. Every anonymous survey is independently checked.
The first premise supplies at least one coastal anonymous survey, and the second rule applies to that particular survey.
Carry only warranted properties
At least one coastal survey is independently checked.
The conclusion preserves the existential quantity. It does not assert that every coastal survey is checked or that most checked surveys are coastal.
Test an extra assertion
A further premise says some independently checked surveys are urgent.
The urgent checked surveys could all be different from the coastal anonymous survey already identified. Sharing a broad category does not force an overlap.
Construct a countermodel
Survey One is coastal, anonymous and checked but not urgent. Survey Two is checked and urgent but not coastal.
Both premises remain true while no coastal survey is urgent. The countermodel defeats the stronger proposed conclusion without challenging the premises.
Test separate witnesses
Give the anonymous survey and the urgent survey different names before assuming overlap.
Distinct witnesses satisfy two existential premises while leaving their intersection empty; an additional link is required to unite them.
Preserve the conclusion's scope
State only the property reached by the same witness through the universal rule.
Following one witness establishes existence of the resulting property, but cannot establish how common that property is among all surveys.
Start with the requirement
An evening laboratory session requires supervision; every supervised session has an attendance record. Session Indigo occurred in the evening.
Translate evening into supervision before using the second rule.
Supply the intermediate and final properties
Indigo was supervised and has an attendance record.
Both implications preserve the identity of the session.
Reject the unsupported reversal
Which conclusion follows?
Every archive open after dusk has a staffed reception desk. Some staffed archives lack climate control. The Halden archive is open after dusk.
Which fact most weakens management's explanation?
Following installation of shaded waiting areas, complaints at a terminal declined. Management credits the shade. During the same period, the terminal also reduced average waiting time by half.
Which must be true?
A restoration grant requires both independent review and public access. Every independently reviewed project has an itemized budget. The Oriole project has a grant.
Which conclusion is supported?
Some regional reports are anonymous. All anonymous reports undergo independent verification. No independently verified report is released on the day it is received.
The curator's inference depends on which assumption?
A curator concludes that a pigment was available locally because it appears on several locally made pots. Imported pigments, however, were routinely used by local potters.
Which question is most useful in evaluating the plan?
A city plans to make bus travel faster by removing cash payment aboard buses. The planner assumes that the removed payment time will become a reduction in total travel time.
Which issue most directly challenges that attribution?
Researchers compared volunteers who chose an evening reading class with residents who did not enroll. Volunteers improved more on a comprehension test. The researchers attribute the entire difference to the class.
Which argument has the same invalid form?
An analyst argues: Every successful fraud requires a misleading record. This transaction has a misleading record. Therefore, it is a successful fraud.
Which fact best reconciles the findings?
A survey finds that the proportion of damaged parcels fell after packaging changed. Nevertheless, the number of damaged parcels rose.
Which claim must follow?
A review committee accepts a proposal only if its methods are reproducible. It rejects every proposal containing fabricated observations. Proposal M was accepted.
Which statement is justified?
An emergency protocol permits remote authorization when either a certified supervisor is unavailable or the communication line fails. During an incident the line worked, but no certified supervisor was available.
Three fresh reserved problems. Choose your method without hints; explanations follow your response.
Which assessment is best supported?
An orchard installed acoustic pest deterrents, after which fruit damage declined. Nearby orchards without deterrents experienced the same decline during a season when a regional pest disease spread.
Why is the conclusion defective?
A licensing rule requires a safety inspection, but an inspection alone never guarantees approval. A commentator concludes that inspections are irrelevant to approval.
Which conclusion follows?
All protected wetlands have monitoring stations. No monitoring station in the northern district is solar-powered. Fen R is a protected wetland in that district.
Explain the decisive restriction or inference in your own notes, then answer three new reserved questions without hints. Review and classify errors before trying a different problem after a study gap.
17. Complete a fresh condition chain, step 3
A recorded session need not have occurred in the evening.
Other sessions may also have attendance records.