Draw the arrow
- Write the condition on the left of an arrow.
- Write the result on the right.
- Use the arrow forwards only unless another rule supplies a return path.
Worked example
If a player wears the blue captain’s band, then they lead the warm-up.
Blue band → leads warm-up. We can conclude that a blue-band player leads the warm-up. We cannot conclude that every player who leads the warm-up wears the blue band; a coach could choose another leader.
A common error
Reversing the rule: “They lead the warm-up, so they wear the blue band.” Test this by inventing one possible different leader. If the original rule still holds, the backwards claim was not guaranteed.
Independent self-check
For each conclusion, label it must, may or cannot tell. “Must” needs a complete forward chain from the stated facts.
Use the method in practice
Conditional rules can be practised in NSW Selective and Opportunity Class material. Take the free test or see the Thinking Skills study overview.