Wait, what? A child can know the Science and still answer the wrong question.
The question says state, so the student writes a long explanation. It says compare, so the student describes two objects separately. It says predict, so the child explains what already happened. It says explain, so the answer gives only the final result.
These are not always content failures. They are often task-decoding failures.
This preserved Hougang Primary 3 Science URL now owns one precise job: understanding Science command words and matching the answer form to the task. The old duplicated 2019 tuition advertisement, stale locality claims, grade promises and unrelated image stack have been removed.
This page is intentionally different from the Hougang P3 page on asking scientific questions. That page teaches how to form good questions. This page teaches how to read the question that has already been given.
Before choosing the Science concept, first identify the job the question is asking the answer to perform.
Command words are instructions, not decoration
Words such as state, describe, compare, predict and explain tell the learner what kind of response is expected.
They control answer architecture.
| Command | Main job | Typical answer shape |
|---|---|---|
| State / Name / Identify | Give the requested fact or item | One precise fact, label or value |
| Describe | Say what is observed or what happens | Feature, pattern, sequence or change |
| Compare | State a similarity or difference | A vs B on the same property |
| Classify | Place into a group using a rule | Category + deciding characteristic |
| Predict | State what should happen next or under a changed condition | Expected outcome, often with direction |
| Explain | Show why or how the result occurs | Cause / evidence → mechanism → outcome |
The exact wording of school questions can vary, but the learner should develop a stable mental model of these jobs.
“State” means give the answer, not the story
If a question asks the student to state the material that is magnetic, the learner usually needs to give the material or object identified by the evidence.
Weak response:
Material B is magnetic because when the magnet was brought near it, it moved towards the magnet, and magnetic materials are attracted to magnets.
If the task is only to state which material is magnetic, much of that may be unnecessary.
A concise answer may simply be:
Material B.
Longer is not safer if the command does not require explanation.
“Name” and “identify” often behave like “state”
These commands usually ask for a label, part, process, property, organism, material or quantity.
- Name the process.
- Identify the structure.
- State the temperature.
- Name the stage in the life cycle.
The learner should resist adding speculative explanation when one precise item answers the task.
This saves time and reduces the chance of introducing a wrong extra statement.
“Describe” means tell me what the evidence shows
Description is usually about what can be observed from the information given.
A graph may ask the learner to describe what happens to temperature over time.
A strong description might say:
The temperature increases from Minute 0 to Minute 5, then remains approximately constant.
This describes the pattern.
If the question only asks for description, the learner does not need to invent a reason for the plateau unless another command asks for explanation.
Description and explanation are different
This distinction is one of the most important in Primary Science.
- Description: what happened?
- Explanation: why or how did it happen?
Example:
Description: The amount of water in the uncovered container decreased more.
Explanation: More liquid water could evaporate from the uncovered container into the surrounding air, so less liquid water remained.
A student who gives the explanation when only description is requested may waste time. A student who gives only description when explanation is required loses the causal middle.
“Compare” means put two things into one relationship
A common weak answer is:
- Plant A is 15 cm tall.
- Plant B is 11 cm tall.
Those are two separate statements.
A comparison makes the relationship explicit:
Plant A is 4 cm taller than Plant B.
Or:
Plant A is taller than Plant B.
The command “compare” asks for relational language: same, different, higher, lower, more, less, faster, slower or another scientifically appropriate relation.
Comparison must use the same property
Students sometimes answer:
Plant A is taller while Plant B has darker leaves.
That describes two differences but does not compare the same property.
A proper comparison keeps the dimension aligned:
- A is taller than B.
- A and B have the same number of leaves.
- A has a higher temperature than B.
The Hougang P3 comparative-property page develops this skill in more depth; command-word decoding tells the learner when to activate it.
“Classify” means use a rule
Classification is not simply naming a group.
A good classification answer should be grounded in the characteristic that decides membership.
Example:
Object X belongs to the magnetic group because it is attracted to the magnet during the test.
If the question only asks which group, the category label may be enough. If it asks how the student knows, the deciding characteristic must appear.
“Predict” means use a model before seeing the result
A prediction is not a memory of what already happened.
It is a statement about what should happen if the model and stated conditions are correct.
Useful structure:
If condition X changes, outcome Y should increase/decrease/remain the same because process M is affected.
Some school questions ask only for the predicted outcome; others ask for prediction and reason. The learner must read the whole instruction.
Prediction and explanation are different
- Prediction: what should happen?
- Explanation: why should it happen?
A student may correctly predict “the water level will decrease” and still fail to explain evaporation.
Or the student may know the mechanism and forget to state the actual predicted outcome.
Separate the two jobs before combining them.
“Explain” needs a mechanism
Explain questions usually ask the learner to connect evidence or a changed condition to an outcome through a scientific process.
A strong basic structure is:
relevant condition or evidence → scientific process → intermediate effect → requested outcome
Weak:
The plant grew less because it was shorter.
Stronger:
The plant received less of the required condition, reducing the process needed to make food, so less material was available for growth.
The exact mechanism must follow the Science given in the question.
“How do you know?” asks for evidence
Students sometimes answer with a textbook fact when the question is really asking what evidence in the data supports the conclusion.
Example:
I know Material A is more transparent because more light passed through it in the test.
The answer points to the observation that justifies the claim.
“Suggest” may allow more than one scientifically valid answer
Some questions ask students to suggest a method, reason or change.
This can be uncomfortable for learners trained to search for one memorised sentence.
A suggestion should still be:
- scientifically relevant;
- consistent with the question;
- specific enough to evaluate;
- supported by a reason where required.
“Suggest” does not mean “guess”. It means generate a plausible response within the scientific constraints.
“Give a reason” is usually smaller than a full essay
If the task asks for one reason, the learner should identify the most relevant mechanism or evidence link.
Do not write three unrelated reasons simply to look thorough.
One precise reason can be stronger than several weak ones.
Watch for paired commands
Questions often combine jobs:
- predict and explain;
- state and give a reason;
- compare and explain the difference;
- identify and justify;
- suggest and explain how it improves the test.
Students who notice only the first command may complete half the task.
A useful habit is to underline every action word before answering.
Command words control evidence use
The same data can support different answers depending on the command.
Given a table of plant heights:
- State the height on Day 5 → give the value.
- Describe the trend → say how height changes across days.
- Compare Plants A and B → state the relation on the same day or interval.
- Predict Day 6 → extend the model cautiously if justified.
- Explain the difference → connect a changed condition to a mechanism.
The information is the same. The answer job changes.
Do not let question length determine answer length
A long story can end with “State the material used.” The answer may still be one phrase.
A short question can ask “Explain why…” and require a complete mechanism.
Answer length should follow the task and scientific reasoning, not the physical length of the question stem.
The command-word translation method
| Question word | Translate silently into |
|---|---|
| State / name / identify | “Give the requested item.” |
| Describe | “Tell what the evidence shows.” |
| Compare | “Put A and B into one relation.” |
| Predict | “Tell what should happen next or after a change.” |
| Explain | “Show the scientific middle between cause and outcome.” |
| Suggest | “Generate a scientifically valid option under the conditions.” |
| How do you know? | “Point to the evidence.” |
The translation should become faster with practice until the learner no longer needs the table.
The answer-shape preview
Before writing the content, decide the expected shape.
- One noun?
- One measurement?
- One comparison sentence?
- One predicted outcome?
- A causal chain?
- A method change plus reason?
This prevents the learner from beginning to write before knowing what kind of answer they are building.
The two-pass read
- Pass 1: What Science situation is this?
- Pass 2: What exactly must I do with it?
Many students perform Pass 1 and skip Pass 2. They identify “magnets”, “heat” or “plants” and immediately retrieve a chapter fact.
The second pass blocks chapter-dump answers.
Five Primary 3 command-word failure modes
1. Explain-everything learner
Every question receives a long reason. Repair by matching answer size to command.
2. Fact-only learner
Even explain questions receive only the final fact. Repair by restoring the mechanism.
3. Separate-description comparer
Describes A and B independently instead of relating them. Repair by using one comparison sentence.
4. Prediction-after-the-fact learner
Restates a known result instead of using the model to predict a new case. Repair by changing one condition before asking.
5. First-command-only reader
Completes “state” but misses “and explain”. Repair by underlining every action word.
A Phase 4 Primary 3 command-word lesson
- Spot: underline the action word.
- Translate: restate the job in simple language.
- Shape: decide whether the answer is a fact, relation, prediction or mechanism.
- Select: choose only evidence needed for that job.
- Build: write the answer in the matching form.
- Check: ask whether every part of the command was completed.
- Trim: remove explanation when not required.
- Expand: restore mechanism when explanation is required.
- Switch: answer the same data under a different command.
- Transfer: repeat across materials, magnets, life cycles and simple investigations.
Why small groups help command-word learning
Give three students the same data but three different commands.
- Student A: describe.
- Student B: compare.
- Student C: explain.
The group sees that the same Science can require three different answer forms.
This makes task-reading visible instead of treating wrong answer form as “carelessness”.
What parents can practise at home
- Ask the child to circle the command word before answering.
- Ask “What job is this word asking you to do?”
- Use the same data and change only the command.
- Ask for one-sentence comparisons rather than two separate descriptions.
- Ask whether an explain answer contains a mechanism.
- Ask whether the child answered every command in a paired instruction.
How to tell whether command-word reading is improving
- Short-response tasks become shorter and more precise.
- Explain answers contain mechanisms.
- Compare answers place two items in one relation.
- Predictions are distinguished from descriptions.
- Paired commands are completed fully.
- Chapter dumps decrease.
- Answer length follows task demand rather than question length.
- The learner can explain why two answers from the same data need different structures.
How this page fits the Hougang Science network
This eduKateSingapore page owns Science command-word decoding and answer-shape selection. It complements relevance filtering, comparative-property reasoning, and scientific question formation.
For the complete P3-to-PSLE reasoning map, use Hougang Primary Science Learning Library.
Official curriculum reference
The Ministry of Education’s Science Teaching & Learning Syllabus: Primary Three to Six develops scientific communication together with observation, comparison, prediction, inference and explanation. Command-word fluency helps learners select which scientific practice the question is asking them to perform.
Primary 3 Science improves when the learner reads the job before retrieving the chapter. State is not explain. Describe is not compare. Predict is not report. Explain is not merely name the concept. Decode the instruction first, then let the Science answer the right question.