Goal: group dated feature cards using a stated visible rule, change the rule and preserve uncertainty. Proposed codes: AC9SFU01, AC9SFI03, AC9SFI05. Prepare: Day 21–23 actual-source cards when available, group-rule mat, fictional Model G, Card 24.
- Evidence gate · 3 min. Separate live plant, animal photo/live, adult report and MODEL cards. Do not treat Model G as local living-thing evidence.
- Read · 4 min. Review exact visible features for two plants and animal source if present. Put blocked/unseen feature cards in CANNOT TELL.
- Model · 5 min. Sort fictional Model G by “has broad oval mark”, then change to “has long line”; explain that the drawings did not change, only the rule did. Do not call them species.
- Child try · 7 min. Card 24 asks a child-chosen visible rule for actual source cards (or model-mark cards if real set incomplete), places each with a source reason, then changes one rule. Adult records placements and unknowns.
- Check · 4 min. Offer “this one belongs here because I like it”. Child identifies preference and chooses a visible feature if aiming for Science grouping; preference itself is welcome but separately labelled.
- Exit · 2 min. Child explains to teacher privately or consenting listener what changed in the sort, with actual response recorded.