Job: model straight light paths and ask what the model leaves out. Ready: ordinary Shadow Window aid; actual apparatus optional. Say: “What might reach the screen?”
- 0–3: Choose one part of the learner's shadow job to think about. Recall actual apparatus versus ideal model with two plain names, “our lamp” and “our drawing.”
- 3–8: Offer one brief actual shadow observation if approved; let the learner choose which edge/place to notice. Without apparatus, begin with the exact named source and a prediction, retaining no actual observation.
- 8–12: Encounter the original ordinary Shadow Window source card. It has point source0, bar4 and screen8 in arbitrary model units; show ideal straight rays past the bar edges. The learner may trace, describe or direct a line; no handling, count, ratio or numerical height calculation is required.
- 12–20: Make an own model of a chosen blocked path, or change/reject the supplied model and say why. Try an actual view again if useful, keeping results separately attributed. Ask one real limitation: “Is our lamp a tiny point? Are these edges clear?” Accept an incomplete explanation and a different next question.
- 20–25: Notice an actual model choice/reason and available actual view, not an automatic inquiry award. Keep the model's author purpose separate from what it helped this learner do. Next: choose one thing to change in a comparison.