The demonstration-moment script.

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

1. 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.
2. 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.
3. 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.

Demonstration 1 — The rock & mineral ID defense

Scored against the rock & mineral ID defense rubric · after Unit 04.

Setup. The student identifies unknown specimens on their own bench — their streak plate, their Mohs hardness kit, their hand lens for luster and cleavage-versus-fracture, and the dilute-acid dropper for the carbonate test. You hand over the specimens; they run each test, read the results, and reason to an identification out loud against a dichotomous key while you watch their hands and listen to their reasoning. Because it's their observation and their key work, there is nothing to outsource.

The question ladder:

• Procedure: "Run your tests on this specimen and give me the identification." (Can they get clean, defensible observations — streak, hardness, luster, cleavage or fracture, acid reaction?)
• Reasoning: "Walk the dichotomous key with me — which property split the call?" (Do they reason from the diagnostic properties, not a memorized specimen list?)
• System: "Why does the streak plate, or the hardness kit, discriminate here?" (Do they understand what each test actually measures?)
• Counterfactual: "If this specimen fizzed in dilute acid but you'd called it a silicate, what changes and why?" (This is the rehearsal-proof rung — a memorized answer dies here.)

Demonstration 2 — Timed map & cross-section reading

Scored against the timed map & cross-section rubric · after Unit 06.

Setup. Under a time limit, the student interprets a geologic map, a cross-section, and a seismogram trace — reading the structures, ordering the events, and telling the story the rock record holds. The clock is the integrity mechanism: there is no time to look anything up, and the skill of reading a map and defending the sequence honestly can't be generated.

The question ladder:

• Read & observe: "Read the map and tell me exactly what you see." (The interpretive skill itself — units, contacts, folds, faults, dip directions.)
• Interpret: "What's the order of events, and which relationship told you?" (Can they apply superposition, cross-cutting relationships, and unconformities from the evidence in front of them, not from memory of a worked example?)
• Discriminate: "How do you know this contact is a fault and not a depositional boundary?" (The recurring confusion pair — this is where a shaky student reveals themselves.)

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

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 hardness call — come back when you can reason through how a mis-read scratch test shifts the identification.")
• 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.