
Common mistakes students make in science exams
Over the past 5 years, i have seen many exam scripts from students and i have summarised the problems below:
Problems faced by students in MCQs
1) Lack of understanding of concepts.
Questions require a child to combine knowledge of a few concepts and think fast.
The child needs to have a good grasp of concepts. He needs to make an effort to remember and understand the definition of key words and its implication.
2) Did not read the question properly.
I have heard repeated stories of teachers telling students to underline or highlight the question.
But I see students highlight the whole question! That is decorating the question. No marks are given for that effort.
Worst still, the child does not make effort to highlight as she wants the exam paper to look neat.
*my reaction
Why is highlighting important?
It will help students to determine what concepts are tested and how to explain them.
What to highlight?
- Words that potentially create confusion or mislead you.
Example: “Only substance B passes through the cell wall”
“Only” is an absolute word.
Another example: A potted plant is placed in a glass wall covered in black paper.
I will highlight “covered in black paper”. Many students associate glass wall to be transparent and will mostly skip the “covered in black paper” portion. You can see the entire context of the question has changed because of these few words.
- Description/labels in the diagram
I personally love this. The examiner has removed all the grammars and show the key descriptions in the question. Still, i have seen many students not using the key words as labelled in the diagram to answer the question.
- Write small notes beside the diagram.
To quickly find out what concepts the examiner is testing the students.
Each time the student highlight the words, the student will remind himself the importance of that key words and the concepts involved. It takes some time to develop this habit and we should begin now.
3) Take too long to decide on the answer. (No time management)
I have seen students are stuck on the MCQs and failed to recognise the time is ticking away. It is good to have a habit of checking the clock once in a while to allocate their time wisely.
Problem faced by students in open ended questions
The question demands your child to explain concepts clearly.
The question demands your child to apply few concepts and explain the results clearly.
What do examiners mean by explaining the concept?
1) To explain the concept, the child needs to understand the concept completely. I noticed many students have incomplete understanding of concepts.
What is understanding concept?
- Know the meaning of the key word in the concept
- Identify the concept in real life/experiment correctly
- Explain the concept.
However, many students can identify the concept but do not know how to explain them.
Example on condensation concept
A student wrote: “Water vapour condenses to form water droplets.”
What is wrong with the above answer?
When I ask the students to explain condensation, you can see their mouths stuttered. “Ehh… ahhh…. like that lor”
But when i asked them to identify the condensation process in their daily lives, they can pinpoint out correctly.
“Teacher Andy, you see this water bottle? I added cold water and there are water droplets!”
“Teacher Andy, you see the clouds in the sky, that is made of many water droplets”
“Teacher Andy, you see my spectacles, it turned misty after I breathe out air”
But that is not the correct way to explain in science exam. They know the concept but lack scientific communication skills. They can’t explain it.
Why?
Because they never make effort to know and remember the definition.
How should should the student answer clearly?
Definition of condensation states, “A process where a substance loses heat and changes from a gaseous state to a liquid state.”
Hence it is good to write “Water vapour loses heat and condenses into water droplets”. Don’t just state condense as what many other students do.
2) Students do not communicate the answer clearly. When answering the question, many of them will skip steps or leave out key descriptive words that can confuse the examiners.
Example
Explain how water droplets are formed after placing the above set up in the open field for a few hours?
Answer by students: The water vapour loses heat and condenses to form water droplets.
The student must be thinking:
Hurray! I get the correct concept. I use the correct key words. I am going to score this question.
Unfortunately, the answer does not give the child full marks.
Why?
Two mistakes with the above answer:
Mistake 1
The student has skipped steps. The question set-up starts off with liquid water. The student should write, “Water gains heat from the sun and evaporates into water vapour” before proceeding to write condensation process.
Mistake 2
The child did not mention where will the water vapour condense on. Is it the inner or outer surface? And on which surface?
You can see there are loopholes in the thought process. The communication is not clear for the examiner to visualize the entire thought process in his head. As a result, no marks are awarded.
Always remember your answer must relate back to the exam question.
Hope this has been helpful!

Join the ScienceShifu Channel to get the latest learning tips.
Benefits of joining Telegram:
Telegram is similar to Whatsapp.
Simply by changing your privacy setting in your Telegram app, your phone number is never shown to anyone.
Some of the links we send via emails might be outdated over time.
It might be easier for you to find out the latest updates through the Scienceshifu channel.
Click below to join the ScienceShifu channel: