Year 1 · 40 minutes · Algorithms
When should a rule take a different path?
A branch is a question with different paths. Our pretend planner checks rain and temperature before suggesting an indoor or outdoor activity. Following a rule correctly does not mean that the rule is sensible. People need to choose the conditions and test situations the first rule forgot.
Draw a forked path on paper. Prepare fictional weather values: rain at 20°C, dry at 22°C, dry at 39°C. Explain that this classroom model is not an official heat or school-play policy.
Follow a two-step instruction and answer a yes/no question. Useful earlier investigations: f-trail Use pairs: one child chooses or points while the other traces or checks. Swap after one case. An adult records the child’s words; drawing and movement are equally valid evidence.
Australian Curriculum Version 9 · Digital Technologies: AC9TDI2P02, AC9TDI2P03. 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.
Use a floor fork labelled rain/no rain and follow two weather cards.
Ask: “Does every card walk along both paths?”
Listen for: “No, the answer chooses a path.”
Record what a rain-only planner will do at 39°C with no rain.
Ask: “What does this rule check, and what does it ignore?”
Listen for: “It checks rain and ignores heat.”
Change the temperature one step at a time and watch the highlighted decision path. Keep rain fixed. Then hold temperature fixed and test rain.
Ask: “Which question changed the suggestion?”
Listen for: “The temperature question crossed its number.”
Remove the heat check and test the dry hot card. Discuss why mechanically correct execution can be unsuitable.
Ask: “Did the computer make a mistake following the rule?”
Listen for: “No; our rule forgot the hot day.”
Choose an illustrative heat threshold and test rain, mild dry and hot dry cards. Draw the improved tree.
Ask: “Does your repair still allow the mild dry day?”
Listen for: “Yes, it goes along the cooler branch.”
Each pair names the human who should decide actual playground practice.
Ask: “Who is responsible for a real decision?”
Listen for: “The teacher or school, not this pretend planner.”
A rule works in every situation.
Predict the rain-only planner’s action for a dry 39°C day before adding the temperature branch.
Dry weather can still be too hot for an activity; correct execution exposes an incomplete rule.
Add a heat branch and show three traces that protect the hot case while preserving the mild case.
Give a previously unseen temperature and ask for the complete branch trace. If the learner guesses from common sense, ask them to follow the displayed questions literally.
Use sun/rain pictures alongside words and only cooler/hotter values. Accept pointing along the path.
Add equipment availability on paper. Find a case requiring a third outcome rather than only indoors/outdoors.
An annotated playground decision tree with three traces.
All temperatures are fictional teaching inputs. Actual weather decisions follow school policy and adult judgement.
Test 4,096 synthetic temperatures in both rain states, exposing hot dry cases missed by a rain-only rule. Change the heat branch and compare exact counts.
| Criterion | Beginning | Secure | Extending |
|---|---|---|---|
| Tracing | Guesses an outcome | Follows the displayed branch | Explains the exact threshold case |
| Rule repair | Adds an unrelated condition | Repairs the hot-day failure | Tests the repair against all three weather cases |
Australian Curriculum Version 9 · Digital Technologies
References: AC9TDI2P02, AC9TDI2P03. Read the current source (checked 2026-09-07).
Evidence to assess: An annotated playground decision tree with three traces.
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: Follow a two-step instruction and answer a yes/no question. Ask the learner to demonstrate it before choosing the level of support.
Preparation: allow about 10 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.
For young learners, show one picture or case at a time. Accept pointing, movement, a drawing or adult transcription. Read the question aloud; explain the numeric model privately to the adult. Do not assess keyboard speed or independent reading.
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.
Choose inside when rain is true OR temperature reaches the selected boundary.
Starting parameters: Inside from temperature = 35
3 cases calculated from your supplied inputs. Compare the evidence with your prediction.
| rain | temperature | decision | my prediction |
|---|---|---|---|
| True | 20 | inside | inside |
| False | 22 | outside | outside |
| False | 39 | inside | inside |
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 rain: True; temperature: 20; decision: inside; my prediction: inside.” 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, rain: True; temperature: 20; decision: inside; my prediction: inside. I can trace it using this mechanism: Choose inside when rain is true OR temperature reaches the selected boundary. 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: Draw a rule with two questions. Test rain on a warm day and a dry day at the boundary. Require the original and changed evidence and this boundary: These are fictional rules, not weather safety advice.
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.