Elaborative Interrogation
Ask "why?" and "how?" to deepen understanding
What the Research Says
Most students revise by memorising facts: equations, definitions, names. But science exams reward explanation — you need to say WHY things happen and HOW they connect. Elaborative interrogation forces you to ask these questions while revising, which builds the deeper understanding that turns a basic answer into a top-band response.
Evidence Base
| Study | Finding | Impact |
|---|---|---|
| Pressley et al. (1987) | Students who asked "why?" while reading recalled 72% of material, vs. 37% for those who just read | Nearly double the recall |
| Dunlosky et al. (2013) | Rated elaborative interrogation as MODERATE utility — highly effective when students already have some background knowledge | Ideal for revision (not first learning) |
| Chi et al. (1994) | Self-explanation — explaining material to yourself — produced better learning than simply studying examples | Explaining builds understanding |
Step-by-Step Method
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1
Read a section of your notes — Pick one lesson or part of a lesson. Read through it once to remind yourself of the content.
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2
Stop at each key fact — Every time you hit an important equation, observation, or claim, pause. Don't just move on.
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3
Ask "Why?" or "How?" — Why does this happen? How does this link to a concept you already know? Why was this experiment designed this way? How does changing one variable affect the others?
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4
Answer from memory first — Try to explain the answer in your own words before checking your notes. Write it down in one or two sentences.
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5
Build a causal chain — Link your "why" answers together: A happens because of B, which leads to C, which causes D. This is exactly the kind of analysis science examiners reward.
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6
Self-test — Close your notes and try to reconstruct the causal chain from memory. Check for gaps.
When and How Often
Each topic takes about 15 minutes with this method. Use it after you've already studied a topic at least once — you need some background knowledge for the "why" questions to work. Best combined with retrieval practice: do a brain dump first, then use elaborative interrogation on the parts you recalled.
Fact: A spring obeys Hooke's Law — the extension is directly proportional to the force applied, up to the limit of proportionality.
Why? Why does the relationship break down beyond the limit of proportionality?
Answer: Within the limit of proportionality, the bonds between atoms in the spring stretch but the internal structure stays intact. Beyond this point, the spring is permanently deformed — the atoms are displaced far enough that they cannot return to their original positions, so the extension is no longer proportional to the force. This is called the elastic limit.
How does PAG P4 (Hooke's Law investigation) test this? → Masses are added to a spring in steps; extension is measured with a ruler after each mass. A force–extension graph is plotted. The straight-line section shows proportionality; the curve shows where the limit has been exceeded.
Why is the area under a force–extension graph important? → It equals the elastic potential energy stored in the spring: E = ½ke², where k is the spring constant. A stiffer spring (larger k) stores more energy for the same extension.
How does this link to energy conservation? → When the spring is released, elastic potential energy converts to kinetic energy, then to other forms — demonstrating the conservation of energy principle.
Force applied → spring extends proportionally (Hooke's Law) → limit of proportionality reached → permanent deformation → elastic potential energy stored (E = ½ke²) → energy released as kinetic energy when spring returns → energy conserved throughout
Why this works: Instead of just memorising F = ke, you now understand the underlying physics — exactly what "explain" and "describe and explain" questions demand.
Common Mistakes
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Only asking "what" questions — "What is Hooke's Law?" tests recall but doesn't build understanding. Always push to "why" and "how".
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Accepting vague answers — "Because the force increases" is not an explanation. Push yourself to give specific mechanistic reasons.
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Skipping the self-test — Building the causal chain is only half the work. You need to close your notes and reconstruct it from memory to lock it in.
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Not connecting across lessons — The best causal chains link concepts from different topics. Hooke's Law connects to energy stores, which connects to conservation of energy across all of Physics.