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. Mastery 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.
The questions progress from recall to explanation and application. Use them to identify what the student understands and where further instruction is needed.
Demonstration 1 — Titration defense
Scored against the titration-defense rubric · after Unit 07.
Setup. The student runs a titration to the endpoint on their own apparatus — their burette, their swirl, their colour call. You name the analyte and indicator; they perform the titration, read the burette, and work the concentration from their titre out loud while you watch their hands and listen to their reasoning. Judge the observed work and explanation together; do not infer independent understanding from a finished result alone.
The question ladder:
- Procedure: "Titrate this to the endpoint and give me your reading." (Can they get a clean, defensible endpoint?)
- Calculation: "Work the concentration from your titre — show me the stoichiometry." (Do they connect moles to the balanced equation, not a memorized formula?)
- System: "Why this indicator for this acid–base pair?" (Do they understand the equivalence point versus the endpoint?)
- Counterfactual: "If you over-shot the endpoint by two millilitres, how does your answer change and why?" (This asks the student to apply the idea to a changed situation.)
Demonstration 2 — Qualitative analysis identification
Scored against the qualitative-analysis rubric · after Units 02–04.
Setup. Under a time limit, the student identifies an unknown by running characteristic tests — flame tests, precipitation reactions, gas tests — and reading the results. Follow the published timing and any approved accommodations. A time limit does not establish independent work by itself; observe the technique and ask the student to explain the result.
The question ladder:
- Test & observe: "Run the tests and tell me exactly what you see." (The hands-on skill itself — colour, precipitate, gas.)
- Identify: "What is it, and which observation told you?" (Can they justify the call from the evidence in front of them, not from memory of a worked example?)
- Discriminate: "How do you know it isn't the ion that gives a similar result?" (The recurring confusion pair — use the answer to identify the specific misconception.)
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. Ask the student to connect the explanation to specific entries. Record what the evidence supports and what needs further checking.
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: Mastery vs. Proficient
| Mastery | Proficient (“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 chemistry 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 the titration calculation — come back when you can reason through how an over-titration shifts the result.")
- 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.