Goal: turn an invented “always stays” claim into a specific safe investigable question and identify what the poster cannot prove. Proposed codes: AC9SFH01, AC9SFI01, AC9SFU03. Prepare: Model T poster, source-claim mat, Card 31.
- Boundary · 3 min. Say PRACTICE SIGN and distinguish it from real school safety signs; no one marks or wipes a real sign.
- Read source · 4 min. Present Model T's rectangle, thick line and exact claim. Child says what is printed, not what happened.
- Model · 5 min. Teacher turns “always stays” into “What happens to this dry mark on this approved broad surface after one adult gentle dry wipe?” Put ACTUAL RESULT at NOT TESTED.
- Child try · 7 min. Card 31 routes invite a new source-specific question and one prediction. Adult labels question/prediction, not observation; material label remains UNKNOWN until verified.
- Check · 4 min. Ask whether a drawn line tells us a material's property. Child names missing surface, mark, action, date and result.
- Exit · 2 min. Save question for adult preflight; no wiping occurs by surprise.