How to use:
- Choose a round length (10, 15, or 20 questions) and a question mix, then click Start
- Treat every premise as absolutely true — even when they use made-up categories or sound unrealistic
- Pick one of the four options. Only one is logically airtight; the others either aren't guaranteed by the premises or contradict them
- Read the feedback after each answer — it explains why the right option works, which is where the learning happens
- Questions are generated fresh each round, so retakes measure real skill, not memory
The two question styles:
- Find the Conclusion: you're given premises and four candidate conclusions. Exactly one necessarily follows — it must be true in every situation where the premises are true. The others are traps: reversed relationships, statements the premises contradict, or claims that merely aren't ruled out
- Fill the Gap: you're given a premise and a conclusion, but the argument has a hole — the conclusion doesn't follow yet. Pick the one additional premise that closes the gap. This trains you to hear the unstated assumption an argument silently relies on
What "necessarily follows" means:
- It's a strict standard: if you can imagine any situation where the premises hold but the candidate conclusion fails, that candidate doesn't follow
- Plausibility is not enough — a conclusion that's merely likely, sensible, or consistent with the premises still fails the test
- Made-up category names (Lorps, Mibs) appear deliberately: they strip away real-world knowledge and force a pure structural judgment
Tips:
- In Find the Conclusion, eliminate first: cross off anything that contradicts a premise, then anything that reverses a relationship, and test what remains with the counterexample question
- In Fill the Gap, work backwards: ask what fact would have to be true for the conclusion to be forced, then look for exactly that among the options
- Watch direction. "All A are B" runs one way; most wrong answers in both styles come from silently running a relationship in reverse
- Gap questions are the everyday skill: real arguments almost never state all their premises, and the missing one is usually where they're weakest