My Child Understands the Lesson — So Why Can’t They Answer the Exam Question?
Understanding the science and scoring marks for the science are not quite the same skill.
One of the most frustrating conversations for a parent goes something like this:
“My child understands the subject. They can explain it perfectly well at home. Their teacher says they participate in lessons. So why are they only getting 50% in the tests?”
It can be equally frustrating for the student.
They revise. They recognise the topic when it appears. They may even look at the mark scheme afterwards and say:
“But I knew that!”
And very often, they did.
The problem is that an examination is not simply testing whether a student knows some science. It is testing whether they can recognise what a particular question requires, retrieve the appropriate knowledge, select the relevant parts, apply them to an unfamiliar situation and communicate the answer in a form that earns marks.
Those are related skills, but they are not identical.
I regularly encounter students whose scientific knowledge is considerably better than their examination marks initially suggest. In those cases, teaching them another chapter of science is not necessarily the answer.
Sometimes we need to teach them how to turn what they already know into marks.
There Are Really Two Questions in Every Exam Question
When a student reads:
“Explain why increasing the temperature increases the rate of a chemical reaction.”
there are actually two problems to solve.
The obvious one is:
Do I understand the effect of temperature on reaction rate?
But there is another:
What does the examiner expect me to do with that knowledge?
A student might write:
“Because the particles move faster when they are heated.”
There is some correct science there.
But depending upon the level of the examination and the number of marks available, it may not be enough.
A better answer might develop the chain:
“Increasing the temperature gives the particles more kinetic energy. The particles move faster and collisions occur more frequently. A greater proportion of collisions also have sufficient energy to overcome the activation energy. Therefore there are more successful collisions per second and the reaction rate increases.”
The student may have understood all of that during the lesson.
The examination skill is recognising how much of that understanding has to appear on the paper.
The examiner cannot award marks for what is inside the student's head.
They can only mark what has been written down.
Knowing Something Is Not the Same as Retrieving It
There is another important distinction.
A student sitting in a lesson may genuinely understand an explanation while the teacher is giving it.
They may follow every stage.
They may answer questions correctly when prompted.
But examinations remove many of those prompts.
There is no teacher saying:
“Think about activation energy.”
There may be no diagram reminding them of the process.
There is nobody asking:
“What happens next?”
The student has to retrieve the information independently.
That is why I sometimes ask a student to explain something to me without looking at their notes.
If I ask:
“What is osmosis?”
and they can explain it clearly, that is encouraging.
But then I might show them a potato experiment they have never seen before and ask:
“Explain why the mass of the potato cylinder increased.”
Now we are testing something slightly different.
The student has to recognise that this unfamiliar-looking question is really asking them to apply their knowledge of osmosis.
That ability to transfer knowledge from the familiar to the unfamiliar is enormously important in examinations.
Command Words Matter More Than Many Students Realise
A surprisingly large number of marks are lost because students answer the topic rather than the question.
The command word tells them what sort of response is required.
For example:
- State — give the required fact, usually briefly.
- Describe — say what happens or identify a pattern, without necessarily explaining why.
- Explain — give reasons and connect cause to effect.
- Compare — identify relevant similarities and/or differences, usually making direct comparisons.
- Suggest — apply scientific knowledge to a situation where the answer may not have been explicitly taught.
- Evaluate — consider evidence or competing factors and reach a justified judgement.
- Calculate — use the relevant data and relationship, showing enough working for the method to be followed.
The difference between describe and explain is particularly important.
Suppose a graph shows that enzyme activity rises as temperature increases and then falls sharply.
A question asking the student to describe the graph might require something such as:
“Enzyme activity increases as temperature rises until it reaches a maximum at approximately 40 degrees C. Above this temperature, activity decreases rapidly.”
That tells us what the graph does.
But if the question says:
“Explain the change in enzyme activity.”
the student needs scientific reasoning.
They need ideas such as increasing kinetic energy, increased successful collisions between enzyme and substrate and, at higher temperatures, changes to the enzyme's active site caused by denaturation.
A beautiful description of the graph may earn very few marks if the examiner asked for an explanation.
The student might know all the biology and still lose the marks.
The Question Is Often Designed to Hide the Topic
This becomes increasingly important as students move from GCSE towards A-level.
At an elementary level, a question might effectively announce:
“This is a question about photosynthesis.”
More demanding questions are often less helpful.
Instead, students may be presented with an investigation involving plants grown under different coloured lights, followed by data on growth rate.
Now the student must decide which parts of their knowledge are relevant.
The same happens in physics.
A student may have revised:
momentum = mass x velocity
perfectly well.
But the examination might present a road-safety investigation involving a trolley, a collision, sensors and several pieces of apparently distracting information.
The difficulty is no longer simply remembering the equation.
The student has to recognise:
“This is a momentum problem.”
That identification stage is something good examination practice should deliberately develop.
Some Information in a Question Is There to Help You — Some Is There to Test You
Students frequently assume that every number, sentence and diagram must somehow appear in their answer.
That is not necessarily true.
Consider a physics question containing:
- the power of an appliance;
- its operating time;
- its mass;
- its colour;
- the room temperature.
If the question asks for the energy transferred electrically, perhaps only power and time are needed.
The relevant relationship is:
energy = power x time
If the appliance has a power of 1500 W and operates for 180 s:
energy = 1500 x 180
energy = 270000 J
or:
energy = 270 kJ
The student's task includes deciding which information matters.
This is one reason simply learning equations is not enough.
Students need practice in selecting the equation themselves.
There is a considerable difference between:
“Use E = P x t to calculate the energy.”
and:
“Calculate the energy transferred.”
The second requires an additional decision before the calculation even begins.
The Four-Mark Question That Produces a One-Mark Answer
This is another pattern I see frequently.
A student gives a correct answer — but not enough of one.
Imagine the question:
“Explain why a person's breathing rate increases during exercise.”
A student writes:
“Because the muscles need more oxygen.”
Correct.
But perhaps the question is worth four marks.
That should immediately suggest that the examiner is probably expecting a chain of reasoning.
An improved response could include:
“During exercise, muscle cells contract more frequently and require more energy. The rate of respiration therefore increases. More oxygen is required for aerobic respiration and more carbon dioxide is produced. Breathing rate and depth increase to supply additional oxygen and remove the extra carbon dioxide.”
The original student may understand every one of those ideas.
Their problem is not biology.
Their problem is developing the answer far enough.
One useful habit is therefore to look at the number of marks available.
It is not a perfect rule that a four-mark question requires exactly four separate statements, but the mark allocation gives the student an important clue about the expected depth.
At the Other Extreme: Writing Everything You Know
Some students respond to uncertainty by doing the opposite.
They write everything they can remember about the subject.
Ask about diffusion and they produce half a page covering diffusion, osmosis and active transport.
Ask why a particular material is a good thermal insulator and they begin explaining conduction, convection and radiation whether they are relevant or not.
This creates several problems.
It wastes time.
It can obscure the actual answer.
And sometimes the student introduces incorrect statements into what would otherwise have been a perfectly good response.
One of the skills I try to develop is asking:
“What is the minimum science needed to answer this particular question completely?”
Not the minimum possible answer.
The minimum complete answer.
That is a very different idea.
Sometimes the Missing Mark Is in the Connecting Words
Science examination answers frequently depend upon logical chains.
Words such as:
because
therefore
so
which means
as a result
can expose whether the reasoning is complete.
Consider:
“The wire has a greater resistance because it is longer.”
That may be appropriate at one level.
But at a more advanced level we might want the student to develop why length affects resistance.
Similarly, in chemistry:
“The chlorine atoms are electronegative, therefore…”
The word therefore forces us to ask what follows.
A student who knows several disconnected facts may still struggle until those facts are connected into an argument.
This is why I often encourage students to build answers as chains:
cause -> scientific mechanism -> consequence -> answer to the question
That simple structure can transform many "explain" questions.
Data Questions Create Another Difficulty
Some students are much happier answering questions based on familiar notes than questions involving graphs, tables or experimental results.
Yet modern science examinations frequently require students to analyse unfamiliar data.
A student might understand the greenhouse effect perfectly well but struggle when presented with a graph of atmospheric carbon dioxide and global temperature.
The problem may be interpreting scales, identifying trends or recognising that correlation does not automatically demonstrate causation.
I therefore like to separate two questions:
What does the data actually show?
and:
What scientific knowledge helps us explain it?
Students sometimes jump straight to what they know and fail to read the evidence in front of them.
Others do the opposite: they describe every number on the graph without using their scientific knowledge.
Good answers often require both.
Practical Questions Can Reveal the Same Problem
A student may have carried out a required practical successfully and still struggle with an examination question about it.
Why?
Because the examination rarely asks:
“Please reproduce the practical exactly as you performed it.”
Instead, it may change the equipment.
It may introduce a different independent variable.
It might ask how reliability could be improved.
Or it might present somebody else's flawed method and ask the student to evaluate it.
The deeper skill is understanding the principles of experimental design:
What is being changed?
What is being measured?
What needs to be controlled?
How can uncertainty be reduced?
Are repeats needed?
Is the method safe?
Would the results genuinely answer the proposed question?
Once students understand those ideas, they become much less dependent upon memorising a particular practical as a recipe.
“But They Get Everything Right When We Do It Together”
This is something parents understandably find confusing.
The crucial words are often:
“when we do it together.”
There is a difference between recognition and independent recall.
If a parent says:
“Isn't this the one where you use kinetic energy?”
the biggest intellectual hurdle may already have been removed.
If a teacher says:
“Look again at the units,”
the student has been given a clue.
If a tutor asks:
“What does the word evaluate mean?”
the student's attention has been directed towards the command word.
All of those prompts are valuable during learning.
But eventually they need to disappear.
One useful method is therefore to reduce support progressively.
First we solve a question together.
Then I give a small hint.
Then I only ask a question such as:
“What is the examiner actually asking you to find?”
Finally, the student tackles the problem completely independently.
That final stage is essential.
Exam Technique Is Not About Learning Tricks
I sometimes hear "exam technique" discussed as though it means finding shortcuts around learning the subject.
It should mean almost the opposite.
Good examination technique allows a student to demonstrate the science they genuinely understand.
There is no magic phrase that substitutes for knowledge.
But there are habits that prevent good knowledge being wasted.
Reading the command word.
Checking the number of marks.
Looking carefully at units.
Identifying the topic before beginning.
Selecting only relevant information.
Showing calculation working.
Using data from the question where appropriate.
Building explanations as logical chains.
Answering the question actually asked rather than the question the student hoped would appear.
And leaving enough time to check the paper.
These habits become powerful precisely because they allow knowledge to be used effectively.
Why Doing More Revision May Not Solve the Problem
When a disappointing test comes home, the instinctive response is often:
“You need to revise more.”
Sometimes that is correct.
But not always.
Imagine two students who both score 55%.
Student A cannot remember large sections of the course.
Student B knows most of the content but repeatedly:
- misreads questions;
- ignores command words;
- fails to use information supplied;
- gives one-mark answers to four-mark questions;
- loses calculation marks through missing working or units;
- runs out of time.
They have achieved the same test score for completely different reasons.
Giving both students another revision guide is unlikely to produce the same result.
Student A needs more work on knowledge and recall.
Student B may need focused examination practice.
That distinction matters.
This Is Where Individual Tuition Can Be Particularly Useful
A classroom teacher may have many pupils completing the same assessment and a limited amount of lesson time in which to respond to every individual pattern of error.
In an individual tuition session, I can spend much longer looking at how one particular student is answering.
We can take an examination response apart sentence by sentence.
Why did you choose this equation?
What did you think the word "compare" meant?
Why did you include this fact?
Why did you leave this information out?
What made you think this was a question about respiration?
Where did you get stuck?
That conversation can be far more informative than simply putting a cross beside the answer.
Sometimes a student discovers that their scientific understanding is actually quite strong.
That can be enormously encouraging.
Instead of:
“I'm terrible at chemistry.”
the conclusion becomes:
“I need to get better at recognising what these questions want.”
That is a much more manageable problem.
Turning an Incorrect Answer Into a Learning Exercise
One of the most useful activities is not simply correcting an incorrect answer but asking the student to improve it.
Suppose the original answer scores 1/4.
I might ask:
What is already correct?
Then:
What information is missing?
Then:
Which words in the question tell us what sort of answer is required?
Finally:
Can we rewrite it as a full-mark response?
We can then change the situation slightly and try another question.
If the student can transfer the same reasoning to the new problem, we know they are beginning to learn the skill rather than merely memorising the correction.
Parents Can Help With This Too
Parents do not need to teach the science themselves to encourage better examination habits.
Instead of immediately telling a child the answer, try asking:
“What is the command word?”
“How many marks is it worth?”
“What information has the question given you?”
“What topic do you think this is testing?”
“Which parts of your answer actually answer the question?”
These questions encourage the student to develop their own examination thinking.
The goal is not for the parent to become the examiner.
It is to help the student develop the habit of questioning the question.
A Useful Three-Stage Test
When I look at a student's exam performance, I find it useful to think about three stages.
1. Do they know it?
Can they recall and explain the underlying science?
2. Can they recognise when to use it?
Can they identify the relevant idea when it appears inside an unfamiliar problem?
3. Can they communicate it for marks?
Can they construct the answer in the form and depth required?
A weakness at any one of those stages can produce a wrong answer.
But the solution should depend upon which stage is failing.
That is why analysing mistakes is often much more valuable than merely counting them.
Understanding the Science Is Only the Beginning
If your child comes out of an examination saying:
“I knew all that!”
they may be telling the truth.
The important question is what happened between knowing it and writing the answer.
Did they recognise the topic?
Did they understand the command word?
Did they choose the right information?
Did they make the reasoning explicit?
Did they give enough detail?
Did they use the data?
Did they show their working?
Did they manage their time?
Those are skills, and skills can be taught.
The encouraging part is that a student who already understands the science has an excellent foundation. We are not starting again.
We are teaching them how to make that understanding visible.
And in an examination, that can make the difference between:
“But I knew that!”
and:
“I knew it — and I got the marks.”
