Assumptions and Flaws
Assumption and flaw questions test necessary assumptions, sufficient assumptions, causal gaps, sampling flaws, equivocation, number shifts, correlation, and alternatives.
How to study for the LSAT
Use the current LSAC format as your map: make Logical Reasoning automatic, build passage structure habits, then rehearse timed sections and Argumentative Writing source use.
Core concepts
Concept 1
Assumptions and Flaws questions reward the answer that follows the official source, the professional role, and the stated facts.
Exam cue: Identify the candidate role, client or public risk, source rule, calculation, or process step being tested.
Concept 2
The strongest answer identifies the rule, safety concern, ethical duty, calculation, client factor, or process step before acting.
Exam cue: Check whether the fact pattern is using a national standard, jurisdiction rule, handbook policy, or scenario-specific instruction.
Concept 3
Eliminate answers that ignore requirements, skip documentation, overreach the role, or treat convenience as the standard.
Exam cue: Choose the compliant and professionally scoped answer before the convenient or familiar answer.
Risk pitfalls and guardrails
Treating related standards as interchangeable without checking the source.
Guardrail: Avoid answers that rely only on habit, ignore the stated source, skip safety or compliance steps, or choose convenience over the professional standard.
Skipping screening, documentation, authorization, sanitation, recordkeeping, or other required procedure.
Guardrail: Avoid answers that rely only on habit, ignore the stated source, skip safety or compliance steps, or choose convenience over the professional standard.
Choosing an answer that protects convenience instead of client safety, public protection, or the stated professional duty.
Guardrail: Avoid answers that rely only on habit, ignore the stated source, skip safety or compliance steps, or choose convenience over the professional standard.
Memory anchors
Necessary Assumption
A necessary assumption must be true for the argument to work.
Sufficient Assumption
A sufficient assumption, if added, makes the conclusion follow.
Causal Flaw
A causal flaw treats an observed relationship as proof of cause without ruling out alternatives.
Sampling Flaw
A sampling flaw relies on data that may not represent the target group.
Equivocation
Equivocation shifts the meaning of a key term.
Percent Number Shift
A percent-versus-number shift confuses proportions with absolute quantities.
Correlation
Correlation shows association, not proof that one factor caused another.
Alternative Explanation
An alternative explanation offers another reason the evidence could be true.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
A survey found that residents who visit the new park most often report the greatest life satisfaction. The mayor concludes that visiting the park increases satisfaction. Which flaw is most serious?
Every highly rated restaurant in the guide accepts reservations. Luma accepts reservations, so it must be highly rated. The argument is flawed because it does what?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
What is Pass Harbor?
Completely free exam prep for 317 U.S. exams.
- Practice questions
- Flashcards
- Study guides
- Mock exams
- No registration
- No paywall
- Start instantly
“No more expensive exam prep. Quality study tools should be accessible to everyone.”