Target: compare onset and duration without assuming either alone decides severity or frequency. Prepare: Card D and hazard-to-impact aid.
- Launch · 2 min. Compare D1's 20-minute lead and D2's 18-hour lead. Ask whether they need identical communication timing.
- Model · 4 min. D1 onset-to-impact 20 minutes, duration 2 hours; D2 18 hours, 3 days. D3 shaking is 40 seconds in this made-up event. This says nothing about how often any occurs or how many people are affected.
- Guided reading · 5 min. Students order the three by stated duration, then separately ask what preparedness/time information is missing. A 40-second event can still have serious effects.
- Practice route · 7 min. Choose Day 7 route. Compare D1 and D2 on two dimensions and make a conditional communication proposal with a limit.
- Audit · 4 min. Peer calls D1 “one-in-20-year flooding” or D3 “safe because brief”; learner strikes both unsupported claims.
- Exit · 3 min. “Can three invented timelines tell us event frequency?” Key: no; frequency needs an appropriate record/model.