How to answer explain questions is to show why or how something happens, not merely to state what happened. Strong explanations connect cause to mechanism to outcome in a logical chain and use subject evidence or principles where the question requires them.
Students often lose explain marks because they give correct facts without connecting them. A list of causes can still be weaker than one complete causal chain if the examiner is asking how the outcome follows.
This guide explains how to distinguish explain from describe, build because-therefore chains, use data or textual evidence, match depth to marks and stop once the required mechanism is complete.
This guide is written for students, parents and educators who want a practical answer to how to answer explain questions in exams. The aim is to turn the command word into a visible operating system: decode the task, select the right evidence or mechanism, produce the answer at the right depth, check it against the question and then practise again on a changed prompt.
The 60-Second Answer
Identify exactly what needs explaining. State the outcome or claim, then give the reason and the mechanism linking cause to effect. Use because, therefore, so that, leads to or another clear connector where helpful. Add evidence, data or an example if required. Check that every sentence moves the explanation forward rather than merely repeating the question.
Working definition: An explain question asks the learner to show how or why something occurs by connecting relevant causes, mechanisms, evidence or reasons to the stated outcome.
Why Explain Questions Matters
Description tells the reader what is observed; explanation accounts for the relationship that produces or justifies it.
Many mark schemes reward linked reasoning, so isolated facts may earn less than a coherent chain.
Strong explanations are often shorter than weak ones because every sentence performs a causal or justificatory job.
The useful standard is not whether the learner has memorised an answer frame. It is whether the learner can recognise the command in an unfamiliar question and build a response that satisfies it without wasting time or drifting into a different task.
The Hidden Problem: Correct Facts Can Sit Beside Each Other Without Explaining Anything
A student may know several relevant facts and place them in the answer.
If the logical bridge is missing, the examiner must infer how those facts produce the result.
The answer should make the bridge explicit: this happens because X changes Y, which causes Z.
The Operating Model
Decode → State Outcome → Give Cause → Explain Mechanism → Link Consequence → Add Evidence → Check Completeness.
Each stage has a different job. Interpretation identifies the required thinking. Selection chooses the relevant mechanism, evidence or criterion. Construction turns that thinking into a markable response. Checking verifies scope, completeness and precision. Retesting shows whether the routine transfers beyond one familiar question.
How to answer explain questions: Step by Step
1. Identify the exact outcome
Clarify what event, pattern, behaviour or result needs explanation.
Do not explain the whole topic.
2. State the immediate cause
Name the factor directly responsible for the change.
Avoid vague language such as because of the environment unless the relevant feature is specified.
3. Show the mechanism
Explain what the cause does and how that action produces the next step.
This is the heart of an explain answer.
4. Link to the outcome
Complete the causal chain rather than stopping halfway.
Use explicit connectors where helpful.
5. Add evidence where required
Use a value, quotation, observation, example or principle if the task expects support.
Evidence should reinforce the mechanism.
6. Match the marks
Higher-mark explain questions often need multiple linked points or a deeper chain.
Use the allocation as a depth clue.
7. Avoid circular wording
Do not explain the outcome by restating it in different words.
Introduce a genuine cause or mechanism.
8. Check every sentence
Ask whether each sentence tells how, why or what evidence supports the relationship.
Remove decorative facts.
What Strong Performance Looks Like
- The exact outcome is identified.
- A cause is stated.
- The mechanism is explicit.
- Cause and outcome are linked.
- Evidence is relevant.
- Depth matches marks.
- Circular explanations are avoided.
- The answer remains focused.
These are observable behaviours, so they can be modelled, practised and corrected. The learner does not need a special exam instinct; the learner needs reliable decisions that become faster with repetition.
Common Failure Modes
1. Description instead of explanation
The learner states what happened but not why.
Add the mechanism.
2. Fact list
Relevant facts are presented without links.
Connect them into a causal chain.
3. Because-it-does circularity
The answer repeats the outcome as the reason.
Introduce an independent causal relationship.
4. Vague cause
Words such as factors or conditions appear without specificity.
Name the factor.
5. Mechanism stops early
The chain ends before reaching the requested outcome.
Complete the final link.
6. Evidence replaces reasoning
A data value is quoted but not explained.
State how the evidence supports the cause or mechanism.
7. Overlong background
The answer begins with broad topic history.
Start with the required relationship.
8. No mark calibration
A six-mark explanation receives one sentence.
Use marks to estimate required depth.
How the Strategy Changes Across Subjects
Science
Explain mechanisms, variable relationships and causal processes with precise terminology and where useful data or observations.
The subject standard remains decisive. General exam technique can organise the answer, but it cannot replace the discipline-specific knowledge needed to make the reasoning correct.
English
Explain how evidence supports an inference, how a language choice produces an effect or why a response fits the text.
The subject standard remains decisive. General exam technique can organise the answer, but it cannot replace the discipline-specific knowledge needed to make the reasoning correct.
Mathematics
Explain why a method or transformation is valid, not merely what operation was performed.
The subject standard remains decisive. General exam technique can organise the answer, but it cannot replace the discipline-specific knowledge needed to make the reasoning correct.
Humanities
Explain causes, consequences, institutional relationships or why evidence supports a historical interpretation.
The subject standard remains decisive. General exam technique can organise the answer, but it cannot replace the discipline-specific knowledge needed to make the reasoning correct.
Primary School, Secondary School and Examination Years
Primary school
Use simple because-so chains: X happens because Y, which means Z. Keep the mechanism concrete and tied to one question.
Keep the structure simple enough that the child can remember it independently. Adults can model the sequence first, then fade prompts as accuracy grows.
Secondary school
Students should distinguish describe from explain, build multi-step causal chains and use evidence where the subject requires it.
Secondary learners should increasingly decide response depth, evidence selection and scope without relying on a teacher to signal what belongs in the answer.
Before major examinations
Practise mixed command words so the learner must identify explain before writing. Mark specifically for missing links, not just missing facts.
Near major exams, practise the command word in mixed sets so the learner must identify the required response type rather than seeing ten identical questions in a row.
A Focused 60-Minute Practice Session
- 10 minutes — sort describe and explain questions.
- 10 minutes — turn five fact pairs into causal chains.
- 15 minutes — answer two explain questions at different mark values.
- 10 minutes — add evidence to one explanation.
- 10 minutes — compare against a mark scheme or strong model.
- 5 minutes — rewrite one circular explanation.
The exact minutes can change. What matters is that the student experiences decoding, independent construction, feedback, targeted repair and a fresh retest.
Diagnostic Checklist
- Can the learner distinguish describe from explain?
- Is the exact outcome clear?
- Is a cause named?
- Is the mechanism explicit?
- Does the chain reach the outcome?
- Is evidence used appropriately?
- Does depth match marks?
- Is circular wording avoided?
Use the checklist to identify the first decision that failed. A weak explanation may actually begin with a missing command word; a weak evaluation may begin with no criterion; a weak inference may begin with evidence that was never read closely.
Practice Laboratory
Practice 1: Because-therefore chain
Write a three-step explanation using cause, mechanism and outcome.
Remove any repeated wording.
Practice 2: Describe-to-explain repair
Take a descriptive answer and add the missing causal link.
Compare the two versions.
Practice 3: Mechanism gap
Provide the cause and outcome but leave the middle blank.
Fill the scientific, textual or logical mechanism.
Practice 4: Evidence link
Add one data value or quotation and explain exactly what it supports.
Do not leave evidence hanging.
Practice 5: Mark-ladder answer
Write one-, three- and six-mark versions of the same broad idea.
Increase depth, not padding.
Practice 6: Circularity hunt
Find explanations that restate the question.
Replace them with a genuine causal relation.
Practice 7: Chain ordering
Scramble the steps of a process and reorder them.
Explain why the sequence matters.
Practice 8: Fresh-context transfer
Apply the same mechanism to a different example.
Check whether the explanation remains valid.
Three Student Cases
Case 1: Maren describes
Maren knows what happened in Science but writes only the observed trend.
Her tutor asks what caused the trend and what happened next.
Her answers begin earning explanation marks because mechanism appears.
Case 2: Iona lists causes
Iona gives three relevant causes but never shows how any leads to the outcome.
She selects one cause and builds a full chain before adding another.
Her answers become more coherent and efficient.
Case 3: Leonie quotes data only
Leonie includes exact graph values but treats them as self-explanatory.
She adds a sentence linking the evidence to the mechanism.
Data begins functioning as evidence rather than decoration.
How Parents Can Help Without Taking Over
Parents can support explain questions by asking for the learner’s reasoning rather than supplying the answer. Useful prompts include: “What is the command word?”, “What does the question actually want?”, “Which evidence matters?”, “What links this point to the result?”, “What criterion are you using?”, and “How will you know the answer is complete?”
When the learner can perform the decision reliably, remove the prompt. The goal is independent control under exam conditions.
How Tutors Can Use a Three-Student Small Group
In a three-student tutorial, explain questions becomes visible because one learner can answer, another can challenge the reasoning, and the third can check the response against the command and mark allocation. Roles then rotate.
After discussion, every learner completes a fresh item independently so group explanation becomes personal performance.
How to Measure Progress
- Describe/explain confusion decreases.
- Causal links become more explicit.
- Fact lists shrink.
- Mechanism vocabulary improves.
- Evidence is integrated better.
- Circular explanations decline.
- Mark-depth calibration improves.
- Fresh-context explanations become more reliable.
Marks are the final indicator, but process changes often appear first: more direct openings, fewer irrelevant sentences, stronger evidence links, clearer criteria, fewer missing steps and faster recognition of command words.
A Four-Week Implementation Plan
Week 1 — Build single chains
Practise one-cause explanations with clear mechanisms.
Focus on completeness.
Week 2 — Add evidence
Use data, quotations or observations where appropriate.
Keep evidence tied to reasoning.
Week 3 — Add mark depth
Practise longer multi-link explanations and multiple causes.
Avoid padding.
Week 4 — Mix command words
Complete authentic exam sets containing describe, explain, compare and evaluate.
Diagnose command-selection errors.
Evidence and Responsible Use
Cornell’s command-word guidance distinguishes explanation from description and directs students to make ideas plain or clear through reasons and relationships. Its broader exam guidance emphasizes decoding question types before answering, which supports treating explain as a distinct reasoning task rather than a generic invitation to write everything known.
Command-word routines should be adapted to the actual subject, school and examination board. Words such as explain, evaluate, compare and infer have common patterns, but local mark schemes and curriculum definitions remain the final standard for the assessment.
- Cornell: Words to Watch for in Essay Questions
- Cornell: How to Tackle Exam Questions
- Princeton: Preparing for Exams
Frequently Asked Questions
What is the difference between describe and explain?
Describe tells what is observed; explain shows how or why it occurs.
Should every explanation use because?
No, but causal connectors can make the reasoning visible.
How many points do I need?
Use mark allocation and the subject mark scheme to estimate required depth.
Can data count as an explanation?
Data are evidence, not the mechanism by themselves. Explain what the data show and why.
Should I define terms first?
Only if the definition is needed to build the explanation.
What if there are several causes?
Build at least one complete chain before adding more relevant causes.
How do I know the chain is complete?
The final link should reach the exact outcome named in the question.
Can explanations be short?
Yes. A concise complete chain can be stronger than a long unfocused paragraph.
Helpful Reading on eduKateSingapore
- How to Read Exam Questions
- How to Answer Short-Answer Exam Questions
- How to Use Mark Schemes Properly
- How to Check Your Work
An Explanation Must Show the Link
Relevant facts are not enough if the reader has to invent the reasoning between them.
Name the cause. Show the mechanism. Reach the outcome. Add evidence where needed. Check that every sentence answers how or why.
Properly taught kids shine a bright light into the future.
Extended Diagnostic Workshops
Workshop 1: Identify the exact outcome × Fact list
Set up one fresh exam-style question where the learner must practise identify the exact outcome while watching specifically for fact list. Clarify what event, pattern, behaviour or result needs explanation. Require an independent response before any model is shown so the controlling decision becomes visible.
Relevant facts are presented without links. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Provide the cause and outcome but leave the middle blank. Fill the scientific, textual or logical mechanism. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 2: State the immediate cause × Mechanism stops early
Set up one fresh exam-style question where the learner must practise state the immediate cause while watching specifically for mechanism stops early. Name the factor directly responsible for the change. Require an independent response before any model is shown so the controlling decision becomes visible.
The chain ends before reaching the requested outcome. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write one-, three- and six-mark versions of the same broad idea. Increase depth, not padding. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 3: Show the mechanism × No mark calibration
Set up one fresh exam-style question where the learner must practise show the mechanism while watching specifically for no mark calibration. Explain what the cause does and how that action produces the next step. Require an independent response before any model is shown so the controlling decision becomes visible.
A six-mark explanation receives one sentence. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Scramble the steps of a process and reorder them. Explain why the sequence matters. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 4: Link to the outcome × Because-it-does circularity
Set up one fresh exam-style question where the learner must practise link to the outcome while watching specifically for because-it-does circularity. Complete the causal chain rather than stopping halfway. Require an independent response before any model is shown so the controlling decision becomes visible.
The answer repeats the outcome as the reason. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write a three-step explanation using cause, mechanism and outcome. Remove any repeated wording. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 5: Add evidence where required × Evidence replaces reasoning
Set up one fresh exam-style question where the learner must practise add evidence where required while watching specifically for evidence replaces reasoning. Use a value, quotation, observation, example or principle if the task expects support. Require an independent response before any model is shown so the controlling decision becomes visible.
A data value is quoted but not explained. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Provide the cause and outcome but leave the middle blank. Fill the scientific, textual or logical mechanism. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 6: Match the marks × Description instead of explanation
Set up one fresh exam-style question where the learner must practise match the marks while watching specifically for description instead of explanation. Higher-mark explain questions often need multiple linked points or a deeper chain. Require an independent response before any model is shown so the controlling decision becomes visible.
The learner states what happened but not why. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write one-, three- and six-mark versions of the same broad idea. Increase depth, not padding. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 7: Avoid circular wording × Vague cause
Set up one fresh exam-style question where the learner must practise avoid circular wording while watching specifically for vague cause. Do not explain the outcome by restating it in different words. Require an independent response before any model is shown so the controlling decision becomes visible.
Words such as factors or conditions appear without specificity. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Scramble the steps of a process and reorder them. Explain why the sequence matters. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 8: Check every sentence × Overlong background
Set up one fresh exam-style question where the learner must practise check every sentence while watching specifically for overlong background. Ask whether each sentence tells how, why or what evidence supports the relationship. Require an independent response before any model is shown so the controlling decision becomes visible.
The answer begins with broad topic history. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write a three-step explanation using cause, mechanism and outcome. Remove any repeated wording. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 9: Identify the exact outcome × Fact list
Set up one fresh exam-style question where the learner must practise identify the exact outcome while watching specifically for fact list. Clarify what event, pattern, behaviour or result needs explanation. Require an independent response before any model is shown so the controlling decision becomes visible.
Relevant facts are presented without links. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Provide the cause and outcome but leave the middle blank. Fill the scientific, textual or logical mechanism. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 10: State the immediate cause × Mechanism stops early
Set up one fresh exam-style question where the learner must practise state the immediate cause while watching specifically for mechanism stops early. Name the factor directly responsible for the change. Require an independent response before any model is shown so the controlling decision becomes visible.
The chain ends before reaching the requested outcome. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write one-, three- and six-mark versions of the same broad idea. Increase depth, not padding. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 11: Show the mechanism × No mark calibration
Set up one fresh exam-style question where the learner must practise show the mechanism while watching specifically for no mark calibration. Explain what the cause does and how that action produces the next step. Require an independent response before any model is shown so the controlling decision becomes visible.
A six-mark explanation receives one sentence. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Scramble the steps of a process and reorder them. Explain why the sequence matters. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 12: Link to the outcome × Because-it-does circularity
Set up one fresh exam-style question where the learner must practise link to the outcome while watching specifically for because-it-does circularity. Complete the causal chain rather than stopping halfway. Require an independent response before any model is shown so the controlling decision becomes visible.
The answer repeats the outcome as the reason. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write a three-step explanation using cause, mechanism and outcome. Remove any repeated wording. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 13: Add evidence where required × Evidence replaces reasoning
Set up one fresh exam-style question where the learner must practise add evidence where required while watching specifically for evidence replaces reasoning. Use a value, quotation, observation, example or principle if the task expects support. Require an independent response before any model is shown so the controlling decision becomes visible.
A data value is quoted but not explained. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Provide the cause and outcome but leave the middle blank. Fill the scientific, textual or logical mechanism. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 14: Match the marks × Description instead of explanation
Set up one fresh exam-style question where the learner must practise match the marks while watching specifically for description instead of explanation. Higher-mark explain questions often need multiple linked points or a deeper chain. Require an independent response before any model is shown so the controlling decision becomes visible.
The learner states what happened but not why. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write one-, three- and six-mark versions of the same broad idea. Increase depth, not padding. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 15: Avoid circular wording × Vague cause
Set up one fresh exam-style question where the learner must practise avoid circular wording while watching specifically for vague cause. Do not explain the outcome by restating it in different words. Require an independent response before any model is shown so the controlling decision becomes visible.
Words such as factors or conditions appear without specificity. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Scramble the steps of a process and reorder them. Explain why the sequence matters. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 16: Check every sentence × Overlong background
Set up one fresh exam-style question where the learner must practise check every sentence while watching specifically for overlong background. Ask whether each sentence tells how, why or what evidence supports the relationship. Require an independent response before any model is shown so the controlling decision becomes visible.
The answer begins with broad topic history. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write a three-step explanation using cause, mechanism and outcome. Remove any repeated wording. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 17: Identify the exact outcome × Fact list
Set up one fresh exam-style question where the learner must practise identify the exact outcome while watching specifically for fact list. Clarify what event, pattern, behaviour or result needs explanation. Require an independent response before any model is shown so the controlling decision becomes visible.
Relevant facts are presented without links. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Provide the cause and outcome but leave the middle blank. Fill the scientific, textual or logical mechanism. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 18: State the immediate cause × Mechanism stops early
Set up one fresh exam-style question where the learner must practise state the immediate cause while watching specifically for mechanism stops early. Name the factor directly responsible for the change. Require an independent response before any model is shown so the controlling decision becomes visible.
The chain ends before reaching the requested outcome. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write one-, three- and six-mark versions of the same broad idea. Increase depth, not padding. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 19: Show the mechanism × No mark calibration
Set up one fresh exam-style question where the learner must practise show the mechanism while watching specifically for no mark calibration. Explain what the cause does and how that action produces the next step. Require an independent response before any model is shown so the controlling decision becomes visible.
A six-mark explanation receives one sentence. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Scramble the steps of a process and reorder them. Explain why the sequence matters. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 20: Link to the outcome × Because-it-does circularity
Set up one fresh exam-style question where the learner must practise link to the outcome while watching specifically for because-it-does circularity. Complete the causal chain rather than stopping halfway. Require an independent response before any model is shown so the controlling decision becomes visible.
The answer repeats the outcome as the reason. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write a three-step explanation using cause, mechanism and outcome. Remove any repeated wording. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 21: Add evidence where required × Evidence replaces reasoning
Set up one fresh exam-style question where the learner must practise add evidence where required while watching specifically for evidence replaces reasoning. Use a value, quotation, observation, example or principle if the task expects support. Require an independent response before any model is shown so the controlling decision becomes visible.
A data value is quoted but not explained. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Provide the cause and outcome but leave the middle blank. Fill the scientific, textual or logical mechanism. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 22: Match the marks × Description instead of explanation
Set up one fresh exam-style question where the learner must practise match the marks while watching specifically for description instead of explanation. Higher-mark explain questions often need multiple linked points or a deeper chain. Require an independent response before any model is shown so the controlling decision becomes visible.
The learner states what happened but not why. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write one-, three- and six-mark versions of the same broad idea. Increase depth, not padding. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 23: Avoid circular wording × Vague cause
Set up one fresh exam-style question where the learner must practise avoid circular wording while watching specifically for vague cause. Do not explain the outcome by restating it in different words. Require an independent response before any model is shown so the controlling decision becomes visible.
Words such as factors or conditions appear without specificity. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Scramble the steps of a process and reorder them. Explain why the sequence matters. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.
Workshop 24: Check every sentence × Overlong background
Set up one fresh exam-style question where the learner must practise check every sentence while watching specifically for overlong background. Ask whether each sentence tells how, why or what evidence supports the relationship. Require an independent response before any model is shown so the controlling decision becomes visible.
The answer begins with broad topic history. After correction, change one meaningful feature—topic, wording, evidence, mark allocation, data, source or context. Then use this related exercise: Write a three-step explanation using cause, mechanism and outcome. Remove any repeated wording. Finish with a delayed retest so success cannot be explained only by immediate memory of the correction.