Lesson Overview | Tirohanga Whānui
Ākonga act out an if/else rule, then build a one-question Scratch interaction and deliberately test correct, incorrect and unexpected answers.
Seminar focus: the decision point
Ākonga write rules that branch and then test them against cases chosen to make the rule fail, not cases chosen to make it pass.
- Unplugged Seminar move: Rule stated, then attacked with a counter-case
- Evidence it produces: A branching rule plus the case that exposed its gap
Lesson at a Glance | Te Hōtaka
Ngā Whāinga Ako | Learning Intentions
- Describe a condition that can be true or false.
- Use if/else to create two possible paths.
- Test expected and unexpected user input.
Do Now: Decide the truth value
7 min| Expression | Test value | True or false? |
|---|---|---|
| score > 4 | score = 7 | |
| answer = “blue” | answer = “Blue” | |
| touching edge? | sprite is in the centre |
Decide each row, then test the middle row in Scratch and see whether you were right.
🔑 Answer key and the surprise in row 2 (kaiako)
- score > 4 with score = 7 → TRUE.
- answer = “blue” with answer = “Blue” → TRUE in Scratch. This is the row worth the lesson. Scratch’s
=block ignores capital letters, so the comparison a student expects to fail actually succeeds. Do not teach “capitals always matter to a computer” — in this environment they do not. The honest and more useful point is that different languages compare text differently: Scratch ignores case here, while Python, JavaScript and Java do not, so"blue" == "Blue"is False in Python. A program’s rules come from the language, not from common sense. - touching edge? with the sprite in the centre → FALSE.
Row 2 is deliberately counter-intuitive. If a pair predicts FALSE and the block says TRUE, that disagreement is the learning — ask them what evidence would settle it, then run it.
The case that still fails: a trailing space. “blue ” = “blue” is FALSE in Scratch, which is why Activity 3 keeps the extra-space test.
Activity 1: Run a human conditional
10 minIF card colour = greenTHEN move two tilesELSE turn right- Run with a green card, a blue card and no card.
- Record which path ran each time.
- Rewrite the condition so “no card” has a safe, clear result.
Activity 2: Build a one-question interaction
23 minwhen green flag clickedask “Which direction does the sun rise from: east or west?” and waitif <answer = “east”> then↳ say “Correct” for 2 secondselse↳ say “Try again: watch tomorrow's sunrise direction.” for 3 seconds- Build and test the exact interaction.
- Replace it with a question you can verify and explain.
- Write the expected result for one correct and one incorrect answer before testing.
- Add a clear restart path so the next user can try.
Activity 3: Edge-case test
13 minTest blank input, different capitalisation and a correct answer with an extra space. Record which result is fair to the user. Improve the prompt, accepted answers or feedback without silently revealing the answer.
Manaakitanga: Helpful feedback supports another attempt; it does not mock a wrong answer.
Exit: Trace both paths
7 minComplete: “The condition is ___. When it is true, ___. When it is false, ___.” Name one edge case your test exposed.
🎯 Curriculum Alignment
Designing and developing an outcome through spatial and product design, materials, foods, biotechnology, systems, or digital tools
Selection makes the digital outcome responsive. See the unit map.
📦 Materials & Resources
Resources already provided: truth table, human rule and target Scratch blocks above; Scratch, devices, three coloured cards and project logs.
📊 Assessment and Success Criteria
Paearu Angitu | Success Criteria: I can state a Boolean condition, build both if/else paths, and use an edge-case test to improve the interaction.
♿ Inclusion, entry and extension
Entry: Sort prepared inputs into true/false before coding. On-level: Build one tested if/else interaction. Extension: Accept more than one valid answer using an OR operator or add a score variable. Provide a paper truth table, keyboard-only controls and chunked one-path-at-a-time building for neurodiverse learners.
📋 Teacher Planning Snapshot
Use verifiable, low-stakes questions. Do not ask learners to encode assumptions about people or identity. If local reo, knowledge or place names appear, confirm spelling and permission with appropriate local authority. Lesson 6 turns unexpected outputs into systematic debugging evidence.
📚 Sources and teaching basis
Scratch Ideas. The mātauranga Māori lens here is ethical design: conditions should not encode stereotypes, and feedback should uphold mana.