PSLE Learner’s Guide · Volume 0947
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A prism separates white light because the component colours refract by different amounts at its boundaries, producing different outgoing directions rather than creating new colours.
Series routes: Use the complete PSLE Learner’s Guide volume directory, the original PSLE Learning Guide and the Science learning hub.
This guide uses original Primary 6 practice and does not predict a live question. Consult the SEAB PSLE formats examined in 2026 page for official information.
Open the full chapter index
- 1. Begin with white light as a mixture
- 2. Trace two boundaries
- 3. Explain unequal bending
- 4. Distinguish dispersion from reflection
- 5. Use a screen to observe separation
- 6. Protect the order without overclaiming
- 7. Connect dispersion and recombination
- 8. Control the examination explanation
- 9. Worked examples
- 10. Independent practice
- 11. Delayed transfer
- 12. Family guidance and FAQs
CHAPTER 1 OF 12 · Back to contents
1. Begin with white light as a mixture
In the simplified visible-light model, white light contains a range of colours. The prism reveals these components; it does not manufacture them from colourless nothing.
Build the explanation by naming the incident white light and its component colours and refraction at the air-to-glass and glass-to-air boundaries. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking different bending amounts and separated outgoing directions and returning to prism orientation screen distance source width brightness recombination and fair-test evidence. State why the tempting alternative is too strong, incomplete or about a different stage.
- Check the incident white light and its component colours.
- Check refraction at the air-to-glass and glass-to-air boundaries.
- Check different bending amounts and separated outgoing directions.
- Check prism orientation screen distance source width brightness recombination and fair-test evidence.
CHAPTER 2 OF 12 · Back to contents
2. Trace two boundaries
Light refracts when it enters the prism from air and again when it leaves glass for air. The overall deviation depends on both boundary interactions and the prism geometry.
Build the explanation by naming the incident white light and its component colours and refraction at the air-to-glass and glass-to-air boundaries. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking different bending amounts and separated outgoing directions and returning to prism orientation screen distance source width brightness recombination and fair-test evidence. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 3 OF 12 · Back to contents
3. Explain unequal bending
Different visible colours travel and refract differently in the material. Their outgoing paths therefore separate, with violet usually deviated more than red in a typical glass prism.
Build the explanation by naming the incident white light and its component colours and refraction at the air-to-glass and glass-to-air boundaries. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking different bending amounts and separated outgoing directions and returning to prism orientation screen distance source width brightness recombination and fair-test evidence. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 4 OF 12 · Back to contents
4. Distinguish dispersion from reflection
Some light may reflect at a surface, but the coloured spread behind the prism is explained mainly by wavelength-dependent refraction through the prism.
Build the explanation by naming the incident white light and its component colours and refraction at the air-to-glass and glass-to-air boundaries. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking different bending amounts and separated outgoing directions and returning to prism orientation screen distance source width brightness recombination and fair-test evidence. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 5 OF 12 · Back to contents
5. Use a screen to observe separation
A white screen intercepts different outgoing directions at different positions. Greater screen distance can enlarge the visible spacing while also making the bands dimmer or less sharp.
Build the explanation by naming the incident white light and its component colours and refraction at the air-to-glass and glass-to-air boundaries. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking different bending amounts and separated outgoing directions and returning to prism orientation screen distance source width brightness recombination and fair-test evidence. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 6 OF 12 · Back to contents
6. Protect the order without overclaiming
The familiar spectrum order follows the prism orientation and material. Rotating the prism changes the direction of the spread, not the underlying fact that colours deviate differently.
Build the explanation by naming the incident white light and its component colours and refraction at the air-to-glass and glass-to-air boundaries. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking different bending amounts and separated outgoing directions and returning to prism orientation screen distance source width brightness recombination and fair-test evidence. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 7 OF 12 · Back to contents
7. Connect dispersion and recombination
A suitable second prism or optical arrangement can redirect separated colours so that they overlap again, supporting the claim that white light is composed of those colours.
Build the explanation by naming the incident white light and its component colours and refraction at the air-to-glass and glass-to-air boundaries. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking different bending amounts and separated outgoing directions and returning to prism orientation screen distance source width brightness recombination and fair-test evidence. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 8 OF 12 · Back to contents
8. Control the examination explanation
Name white incident light, apply refraction at both boundaries, state unequal deviation of colours, trace the separated rays to the screen and distinguish observed evidence from the simplified model.
Build the explanation by naming the incident white light and its component colours and refraction at the air-to-glass and glass-to-air boundaries. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking different bending amounts and separated outgoing directions and returning to prism orientation screen distance source width brightness recombination and fair-test evidence. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 9 OF 12 · Back to contents
9. Worked examples
Worked case 1: What appears when a narrow beam of white light passes through a prism onto a screen?
Controlled answer. A spread spectrum of colours. Different colours leave in different directions after refraction.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Label red and violet ends cautiously. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “A spread spectrum of colours” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 2: Does the prism create the colours?
Controlled answer. No. It separates colours already present in the incident white light.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Use recombination as supporting evidence. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “No” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 3: How many main refractions occur in a simple prism path?
Controlled answer. Two. The ray crosses an air-glass boundary and later a glass-air boundary.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Draw both normals. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Two” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 4: Which usually deviates more in glass, red or violet?
Controlled answer. Violet. The material bends different wavelengths by different amounts.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Avoid turning this into a universal for every material. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Violet” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 5: Repair: the prism reflects white light into colours.
Controlled answer. The prism mainly refracts and disperses the transmitted light. Reflection is not the mechanism producing the transmitted spectrum.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Trace the path through the prism. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “The prism mainly refracts and disperses the transmitted light” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 6: Repair: only one surface matters.
Controlled answer. Both entry and exit boundaries affect the final ray direction. The ray changes medium twice.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Mark each change. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Both entry and exit boundaries affect the final ray direction” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 7: Why use a narrow incident beam?
Controlled answer. It reduces overlap and makes separated colours easier to distinguish. A wide source can blur neighbouring bands.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Control source width. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “It reduces overlap and makes separated colours easier to distinguish” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 8: Why can increasing screen distance make the spectrum wider?
Controlled answer. Rays travelling in different directions separate farther with distance. Angular separation becomes larger positional separation.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Note the possible loss of brightness. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Rays travelling in different directions separate farther with distance” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 9: What happens if monochromatic red light enters the prism?
Controlled answer. It bends but does not split into a full visible spectrum. The input lacks the range of colours required.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Compare with white light. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “It bends but does not split into a full visible spectrum” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 10: What evidence supports white light being composite?
Controlled answer. It can be dispersed into colours and suitably recombined into a near-white beam. The transformations preserve components.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. State the setup conditions. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “It can be dispersed into colours and suitably recombined into a near-white beam” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 11: Does every transparent block produce an obvious spectrum?
Controlled answer. No. Parallel faces and small dispersion may leave colours overlapping closely.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Compare a rectangular block with a prism. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “No” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 12: Why draw normals at both faces?
Controlled answer. Refraction angles are defined relative to the perpendicular normal. The surface angle alone can mislead.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Label incident and refracted rays. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Refraction angles are defined relative to the perpendicular normal” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck the incident white light and its component colours, refraction at the air-to-glass and glass-to-air boundaries, different bending amounts and separated outgoing directions, prism orientation screen distance source width brightness recombination and fair-test evidence. Decide whether the evidence proves the conclusion or only supports a limited statement.
CHAPTER 10 OF 12 · Back to contents
10. Independent practice
Practice 1: Which variable should change in a material comparison?
Explained answer. The prism material. Source, beam width, prism angle, position and screen distance should be controlled.
Delayed transfer. Measure separation consistently. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 2: What observation indicates stronger dispersion?
Explained answer. A larger angular or positional separation of colours under controlled geometry. It concerns separation, not merely brightness.
Delayed transfer. Define the measurement. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 3: Can a coloured filter produce the same mechanism?
Explained answer. No. A filter selectively transmits colours, while a prism separates directions by unequal refraction.
Delayed transfer. Compare their outputs. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 4: Why might the spectrum look continuous rather than seven sharp stripes?
Explained answer. Visible colour changes continuously across wavelength ranges. Named colours are convenient regions of a continuous spread.
Delayed transfer. Avoid inventing hard boundaries. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 5: What is the nearest wrong shortcut?
Explained answer. Saying prism plus white light gives rainbow without explaining unequal refraction. The mechanism requires boundaries and different deviations.
Delayed transfer. Add the causal chain. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 6: How does prism orientation affect the result?
Explained answer. It changes where the spectrum appears and its spread direction. The geometry redirects all rays.
Delayed transfer. Keep source and screen fixed. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 7: What safety limit applies?
Explained answer. Use a safe classroom lamp or indirect daylight, never look at the Sun through optical equipment. Focused or redirected intense light can injure eyes.
Delayed transfer. Use a screen for observation. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 8: State the full method.
Explained answer. Identify white incident light, trace refraction at entry and exit, explain different deviations of component colours, observe their separated positions on a screen, control geometry and distinguish dispersion from filtering or reflection. Use recombination as a check.
Delayed transfer. Predict a changed setup. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
CHAPTER 11 OF 12 · Back to contents
11. Delayed transfer
On day one, solve clear examples. On day three, mix examples, near-nonexamples and incomplete evidence. On day seven, solve without headings or a word bank. Delay reveals whether the method can be reconstructed independently.
Keep an error log for the first failed stage: reading, representation, rule, execution or checking. The earliest failure identifies the repair.
Interleave this skill with neighbouring ideas that share vocabulary. Classify each item only after naming the distinguishing condition.
In timed work, mark the relationship, apply the rule, write the conclusion and audit one condition. If checking changes the answer, record the overlooked feature.
Create a teach-back card with a near-nonexample on the front and the repaired mechanism on the back. Explain why the tempting answer fails.
Finish with one basic example, one boundary case and one transfer case. Supply explanations that a classmate can verify.
For a second delayed test, reverse the direction: start from a conclusion and invent evidence that would justify it, then evidence that would be insufficient. This exposes the boundary between relevance and proof.
CHAPTER 12 OF 12 · Back to contents
12. Family guidance and FAQs
Guidance for parents and tutors
Ask for the decisive condition before confirming the answer. Use prompts such as “What exactly happened?”, “Which stage or meaning is this?” and “What would prove it?”
Fade support from labelled examples to mixed questions and delayed open response. Independent retrieval after time and topic change is the target.
Praise precise claim control. Narrowing an answer when evidence is incomplete is scientific and academic strength.
Frequently asked questions
Should I memorise the rule?
Memorise the compact rule, then practise examples and near-nonexamples so the conditions remain visible.
What if two answers seem possible?
Return to the exact relationship and choose the option satisfying every stated condition without adding facts.
Why delay practice?
Immediate repetition may depend on the recent explanation; delay tests reconstruction.
How should an error be corrected?
Name the first failed stage and practise it with a changed example.
When is the skill ready?
When the learner can explain, apply and transfer it after a delay.
What is the final audit?
Check relationship, mechanism, claim strength and whole-question fit.
Next routes
Continue at the Science learning hub or return to the series directory.