Year 3 · 55 minutes · Automation
Should one uncertain signal be allowed to trigger an action?
A classifier output is only one part of a system. A controller decides whether and when to act. Our rover sees a synthetic sequence of target scores. A single spike can trigger an unnecessary stop. Requiring several consecutive high readings removes some spikes but delays action and can miss a brief real target. This is a controller simulation, not autonomous navigation.
Print the supplied score timeline and marked target intervals. Use a toy rover to step across it. Rehearse how a low reading resets the consecutive-high counter.
Read a yes/no sensor result and follow a simple rule. Useful earlier investigations: y1-sensor, y1-branch Use pairs with predictor/operator roles. Swap after the first comparison. Each learner draws or writes their own explanation using one exact case.
Australian Curriculum Version 9 · Digital Technologies: AC9TDI4P02, AC9TDI4P03. Selected aspects only. This activity contributes evidence; it does not cover the full descriptor or achievement standard. A programming descriptor is not claimed for merely moving controls. ACARA AI curriculum connection · V9 Technologies These are planning connections, not ACARA endorsement or exhaustive descriptor alignment.
Step a toy along the score strip, stopping on any score over the threshold.
Ask: “Did every high score mean a real target?”
Listen for: “No, there was a short spike.”
Predict what requiring three high readings will change with the scores fixed.
Ask: “What might waiting protect us from? What might it cost?”
Listen for: “It can ignore a spike but stop later.”
Step the timeline with persistence 1, then 3. Record counter values, stops and missed intervals. Save each run for comparison.
Ask: “Why did the count return to zero?”
Listen for: “The next reading was below the threshold.”
Load the short real-target interval. Observe why waiting can miss it completely.
Ask: “Was the short high signal always noise?”
Listen for: “No, this one was a real brief target.”
Choose persistence and threshold for a stated fictional task. Compare on the same timeline and name a residual error.
Ask: “Which mistake does your design accept, and why?”
Listen for: “We accept some delay to avoid false stops, but not for every task.”
Draw sensor → score → counter → action with one trace.
Ask: “Where did our design choice enter?”
Listen for: “At the controller after the score.”
Every prediction should trigger an action.
With scores fixed, predict how changing persistence from one to three readings affects false stops and delay.
A brief real target looks temporally like a noise spike; persistence can remove both.
Set an action policy and justify it with false-stop, missed-target and delay evidence.
Ask the learner to trace the counter across one below-threshold reading. Credit an explicit trade-off rather than insisting on one best setting.
Use six time steps and physical counters; keep threshold fixed while investigating only persistence.
Compare consecutive-high gating with a rolling average and explain their different response to alternating spikes.
An actuator policy with a labelled timeline and before/after error counts.
No physical robot is controlled. The synthetic task is not a road, medical or emergency system and must not be used as one.
Evaluate thousands of seeded noisy timelines in parallel. Sweep persistence lengths and measure false stops and missed targets at a controlled threshold.
| Criterion | Beginning | Secure | Extending |
|---|---|---|---|
| State tracing | Reads only the current score | Tracks consecutive highs and reset | Explains the timing of an action |
| Policy evaluation | Chooses the fewest actions | Compares misses and false stops | Justifies delay and residual risk for a task |
Australian Curriculum Version 9 · Digital Technologies
References: AC9TDI4P02, AC9TDI4P03. Read the current source (checked 2026-09-07).
Evidence to assess: An actuator policy with a labelled timeline and before/after error counts.
Selected aspects only. This activity contributes evidence; it does not cover the full descriptor or achievement standard. A programming descriptor is not claimed for merely moving controls. Moderate the supplied illustrative responses against your school unit and current achievement standard.
These are planning estimates to test with your class. A short session develops one supported claim; it does not compress the whole senior project.
| Stage | 45 minute focus | 60 minute investigation |
|---|---|---|
| Readiness and prediction | 0–5 | 0–5 |
| Trace the supplied example | 5–13 | 5–15 |
| Author and run cases | 13–25 | 15–35 |
| Counterexample and redesign | 25–35 | 35–45 |
| Explain and discuss | 35–42 | 45–55 |
| Export and handover | 42–45 | 55–60 |
For a longer project, use three 50-minute sessions. Session 1 (0–50): readiness, model, hypothesis and initial cases. Export a project and record the next test. Session 2 (50–100): reopen, check settings, author counterexamples and revise the design. Export the changed project and identify unresolved evidence. Session 3 (100–150): independent peer test, final artefact, individual explanation and moderation. If using two 60-minute sessions, stop at minute 60 after saving the first comparison; use 60–120 for redesign, independent test and defence.
Entry check: Read a yes/no sensor result and follow a simple rule. Ask the learner to demonstrate it before choosing the level of support.
Preparation: allow about 15 minutes to run the starter, print the cards and check a project can be reopened. This estimate has not yet been measured in a classroom pilot.
Read the entry question aloud, model one row, and label the units. Offer the case table as a large-print sheet. Keep mathematical derivations optional until the learner can explain the comparison.
For one device, use a projector: one pair predicts, one operates, and the class records on paper. Swap roles after the first comparison. For individual access, support keyboard controls and a written table equivalent to each visual. Learners may explain orally or with an annotated diagram. Never require personal data, a recorded voice, or a photograph.
Mixed readiness: if the entry check is difficult, use the linked prerequisite and the first two case cards; retain the same central question. If secure, ask the learner to design an unseen test and state which explanation it could disprove.
Count consecutive positive readings, resetting to zero on a negative reading. Open the gate when the count reaches the requirement.
Starting parameters: Consecutive readings = 2
6 cases calculated from your supplied inputs. Compare the evidence with your prediction.
| step | reading | consecutive | open | object | false opening |
|---|---|---|---|---|---|
| 1 | False | 0 | False | False | False |
| 2 | True | 1 | False | False | False |
| 3 | False | 0 | False | False | False |
| 4 | True | 1 | False | True | False |
| 5 | True | 2 | True | True | False |
| 6 | True | 3 | True | True | False |
These are authored examples, not work collected from children. Assess reasoning using the lesson rubric, not whether the first prediction was correct.
Beginning: “It worked because the result looks right.” This identifies no exact case, control or measurement. Ask the learner to point to one row and say what happened.
Developing: “In the first case I recorded step: 1; reading: False; consecutive: 0; open: False; object: False; false opening: False.” This cites evidence, but does not yet explain how the result follows from the rule. Ask the learner to trace the relevant step.
Secure: “For the first supplied case, step: 1; reading: False; consecutive: 0; open: False; object: False; false opening: False. I can trace it using this mechanism: Count consecutive positive readings, resetting to zero on a negative reading. Open the gate when the count reaches the requirement. My result supports a claim about these supplied cases. It does not establish that the same result holds outside them.” Look for an accurate trace, the actual settings and a bounded claim; accept equivalent oral or visual evidence.
Extending: The learner constructs and reruns a new case, reports whether the first explanation survives, and defends a revised design. Use this concrete challenge: Write a wait rule. Test an isolated false reading and a real object that lasts for several readings. Require the original and changed evidence and this boundary: Waiting can reduce isolated false readings and also delay or miss a brief real target.
Moderation: first assess independently against each lesson criterion. Compare the exact trace or artefact that led to your judgement. Resolve differences using evidence, not polished language. Keep each learner's individual explanation even when the artefact was produced in a group.