A broad claim uses words like “always” or “everyone”. To qualify it, you check it against the supplied data and rewrite it so it says only what the figures support.
This lesson belongs to evidence-based economic answers. It pairs well with separating a model assumption from an observed fact, because both ask you to stay inside the evidence.
What should you check before agreeing with a claim?
Run four checks on the table, in this order.
- Where: whose figures are these, one shop, one town or a whole country?
- When: how many weeks, months or years do they cover?
- Fair comparison: are the rows measured on the same basis, such as per day or per person?
- Other causes: could something else explain the pattern?
Write one short sentence for each check that matters. A claim that survives all four can be stated with more confidence. A claim that fails one needs a qualifier.
Worked example: the canteen and the weather
A fictional school canteen in Taman Kenari records packet drink sales and average temperature.
| Week | Average temperature | Days open | Packets sold |
|---|---|---|---|
| 1 | 30°C | 5 | 420 |
| 2 | 32°C | 5 | 465 |
| 3 | 33°C | 5 | 510 |
| 4 | 29°C | 3 | 240 |
The claim is: “Hotter weather always raises drink sales.”
Week 4 has the lowest sales, but the canteen was open only 3 days. Raw totals are not a fair comparison, so work per day: 420 ÷ 5 = 84, 465 ÷ 5 = 93, 510 ÷ 5 = 102 and 240 ÷ 3 = 80.
The per-day figures rise as the temperature rises: 80, 84, 93, 102 at 29°C, 30°C, 32°C and 33°C. The data support a link in this canteen. They cannot support “always”, because four weeks from one canteen is a small base.
A qualified answer: “In this canteen over four weeks, daily drink sales rose with temperature, from 80 packets at 29°C to 102 at 33°C. The table cannot show whether this holds in other places or longer periods, and it does not rule out other factors such as exam week.”
Which mistakes cost marks?
The common slip is to read the totals and conclude that week 4 disproves the claim. That answer ignores the days open, so it compares unlike things.
The opposite slip is to accept the claim in full because the trend fits. Fitting four rows does not prove “always”. The fix is the same each time: name the basis, then name the limit.
Check yourself
A fictional cafe records its monthly price and customers. Month A: price RM6, 300 customers. Month B: price RM5, 360 customers. Month C: price RM4, 370 customers.
The claim is “Lower prices always bring more customers.” How far does the table support it?
Answer
Each price cut was followed by more customers. From A to B, customers rose by 60, which is 20% of 300. From B to C, they rose by only 10, about 3% of 360.
So the table supports “in this cafe, over these three months, lower prices went with more customers”. It does not support “always”, because the gain shrank and three months cannot rule out other causes such as school holidays.
What to study next
Move on to developing a short causal chain with a stated limiting condition, then test yourself in the evidence-based answers practice. The graph evidence and fair-comparison lab lets you try the per-day check on your own numbers.
If you want a teacher to read your written answers with you, see online one-to-one Economics tuition.