This is a working draft for Leslie's review. All three demonstrations are scripted; edit the question ladders and example exchanges freely. Each demonstration is scored against its published rubric — this page is how to run it, not the rubric itself.
The demonstration is the part of the course that cannot be faked, outsourced, or generated. A student stands in front of you and shows understanding in real time, against a rubric, out loud. Your job is to run it the same way every time: a setup that makes faking impossible, a question ladder that probes past rehearsal, and a clean binary verdict recorded against the rubric.
The three rules that govern every demonstration
- The student does the work; you only ask. No coaching, no leading questions, no "are you sure?" that signals the answer. You probe understanding — you never supply it.
- The verdict is binary. Mastered or not yet. You are not assigning a score in the room; you are deciding whether the published rubric's bar was cleared.
- A "not yet" is a checkpoint, not a failure. How you deliver it determines whether the student comes back. Name the specific gap, give the re-attempt path, and keep the door open.
Every demonstration below climbs the same shape: from recall at the bottom to a rehearsal-proof rung at the top. Keep climbing until you reach the student’s real ceiling — a memorized answer falls off near the top.
Demonstration 1 — Build-and-test defense
Scored against the build-and-test defense rubric · after Unit 08.
Setup. The student builds a simple working device on their own — a battery-and-bulb circuit, a ramp and cart, a lever, or a wave on a spring — measures how it behaves, and defends both the design and the data out loud while you watch their hands and listen to their reasoning. Because it's their build and their measurement, there is nothing to outsource.
The question ladder:
- Procedure: "Build it and show me it works." (Can they put together a device that actually behaves?)
- Measurement: "Measure how it behaves and read me your numbers." (Can they take a clean, defensible measurement — current, distance, time, or force?)
- System: "Why does it behave this way?" (Do they connect the parts to the result — a complete loop, a balanced force — not a memorized rule?)
- Counterfactual: "If you added a second bulb, or made the ramp steeper, how does your result change and why?" (This is the rehearsal-proof rung — a memorized answer dies here.)
Demonstration 2 — Timed prediction-and-test
Scored against the timed prediction-and-test rubric · after Unit 04.
Setup. Under a time limit, the student predicts a physical outcome from a measurement — how far a cart will roll, how long a pendulum will swing, how bright a bulb will glow — then runs it live and accounts for the gap between the prediction and the result. The clock is the integrity mechanism: there is no time to look anything up, and the skill of predicting from a real measurement and owning the difference can't be generated.
The question ladder:
- Predict: "From this measurement, tell me what will happen — and give me a number." (The prediction itself, made before the run.)
- Test & compare: "Now run it. How close were you?" (Can they take the measurement honestly and compare it to their own prediction?)
- Account: "Why is the real result different from what you predicted?" (Can they reason about friction, air, or measurement error — not hand-wave the gap away?)
Demonstration 3 — Oral lab-notebook defense
Scored against the lab-notebook-defense rubric · end of each unit.
Setup. The student walks you through their own notebook: the question, the method, the data, the anomalies, the interpretation. Because it is their recorded work, the defense is unfakeable — a student who didn't do the thinking can't narrate the decisions behind it.
The question ladder:
- Narrate: "Walk me through what you did and why." (Does the story hold together?)
- Anomaly: "This data point doesn't fit — what happened?" (Did they notice, and can they reason about it honestly rather than hide it?)
- Method critique: "What would you change if you ran it again?" (Do they understand the method's limits and sources of error?)
- Transfer: "How does this connect to the concept from this unit?" (Integration — scored on its own line.)
Reading the room: mastered vs. approaching
| Mastered | Approaching (“not yet”) |
|---|---|
| Answers the counterfactual rung without hesitation — reasons forward from understanding. | Strong on recall rungs, collapses at the counterfactual. The understanding is memorized, not built. |
| Owns anomalies and sources of error, and reasons about them. | Hides or hand-waves the data that doesn't fit. |
| Connects the observation to the mechanism and the lab to the concept unprompted. | Knows the test in isolation; can't trace the physical science behind it. |
Recording the verdict
Mark the rubric in the room while it's fresh — pass or not-yet on each rubric line, with a one-line note on the deciding moment. If the verdict is "not yet," that note becomes the re-attempt instruction. Do not soften the rubric to avoid an awkward conversation; soften the delivery instead.
Delivering a "not yet" so the re-attempt stays likely
- Lead with what was solid before naming the gap — the student needs to know the work wasn't wasted.
- Name one specific thing to close, not a list. ("The counterfactual on your build — come back when you can reason through how adding a second bulb changes the current.")
- Give the date and the path. A "not yet" with a re-attempt slot on the calendar is a checkpoint; a "not yet" with no path is a wall.
- Coach or hint during the demonstration — including tone, eyebrows, and "hmm."
- Ask leading questions that contain the answer.
- Let partial credit creep in. There is no 7-out-of-10 here — the bar is cleared or it isn't.
- Move the bar for a likeable student, a tired afternoon, or a parent in the room.