Stable textbook mechanisms can be stated from your notes. Claims about figures, recommendations or current events need a current authoritative source, and your answer can say so.
This lesson closes the health-themed science sub-cluster. It uses the skills from distinguishing evidence from marketing claims.
How do I sort a claim?
Ask four questions of each statement:
- Does it give a number?
- Does it say what people should do?
- Could it have changed recently?
- Does it refer to a particular person or group?
If any answer is yes, the statement needs a current source. If all are no and the statement describes a basic mechanism, your textbook is enough.
Worked example: six statements
Sort these into “textbook is enough” and “needs a current source”.
| Statement | Sort | Reason |
|---|---|---|
| Enzymes in the stomach help break down food | Textbook | Stable mechanism |
| A recommended daily amount of a nutrient | Current source | Number that can be revised |
| A vaccine schedule for children | Current source | Recommendation that can change |
| Red blood cells carry oxygen | Textbook | Stable mechanism |
| The number of cases of an illness this year | Current source | Figure that changes |
| What a specific person should take for a cough | Doctor or pharmacist | Personal, cannot be answered from a textbook |
Model answer for one statement. “The recommended daily amount of a nutrient needs a current authoritative source, such as the Ministry of Health Malaysia, because recommendations can be revised as new evidence appears.”
The answer names the type of source and the reason. It does not state any number.
The mistake that costs marks
The slip is stating a figure from memory as if it were current. A number remembered from a poster may be outdated or wrong, and a wrong figure loses the mark.
| Wrong | Right | |
|---|---|---|
| Figure handling | State remembered number | Use the number supplied, or say a current source is needed |
| Source | “The internet” | A named authority such as the Ministry of Health Malaysia |
| Personal question | Answer it | Direct it to a doctor or pharmacist |
Check yourself
Sort these: (a) “Lungs exchange oxygen and carbon dioxide.” (b) “The current guideline for how much sleep students need.”
Answer
(a) Textbook is enough: it is a stable mechanism of gas exchange.
(b) Needs a current source: a guideline can be revised, so check the Ministry of Health Malaysia or another authority that publishes it.
What to study next
Return to the sub-cluster overview to see how the four lessons connect, then use the claim evidence revision desk for extra practice.
For a teacher to go through the sorting test with you, see online one-to-one Science tuition.