Three marks, one limitation, about eight minutes. Question 1 is the smallest question on the paper and the easiest to overspend on. The skill being tested is narrow and completely learnable: look at a graph or table and find one honest reason it cannot support a strong conclusion.
📘 What you need to know
Q1 is worth 3 marks and always refers to Source 1, usually a graph or table.
The wording is nearly always: explain one issue that limits the interpretation of the data.
Three moves: what the data shows, one clear limitation, and why that weakens any conclusion.
One limitation only. A second earns nothing because there is no fourth mark.
Use only what is on the page. Do not invent explanations the source does not give.
Do not list strengths. The question asks what limits interpretation.
The three-move answer
Three or four sentences in total. Anything longer is time borrowed from the 15-mark essay at the end of the paper.
Where limitations hide
Four questions to ask any Source 1. One of them will always produce a usable limitation.
The limitations that come up most
No cause and effect. The graph shows an association, not a reason. Correlation does not equal causation.
Small or unrepresentative sample. Whoever was measured may not represent the wider population.
No qualitative detail. The numbers show a pattern but say nothing about why people answered as they did.
A subjective variable measured numerically. Things like self-efficacy or motivation mean different things to different people, so a 0 to 10 scale may not capture them.
Vague or missing labels. A category called “others”, or an axis with no units or time intervals, blocks any precise conclusion.
Reporting differences, not real differences. A condition may look more common in one place because it is diagnosed or reported more there.
That last one is worth learning properly. If a chart shows rates of something across regions, you cannot assume the differences are real — they may be differences in how often the thing is noticed, reported or diagnosed. It is a validity point, and it is a strong one.
Worked examples
WORKED EXAMPLE
Source 1 shows self-efficacy scores, rated 0 to 10, before and after a therapy programme. Explain one issue that limits the interpretation of the data. [3 marks]
1 What it shows
Self-efficacy scores were higher after the programme than before it.
2 The limitation
Self-efficacy is a subjective variable being measured on a fixed numerical scale, and it means different things to different people.
3 So what
A score of 7 for one participant may not represent the same experience as a 7 for another, so the numbers may not be comparable and any conclusion about how much the programme helped is uncertain.
Three moves, three or four sentencesNotice there is only one limitation here. Adding a second would not add a mark.
WORKED EXAMPLE
Source 1 is a pie chart of the percentage of people diagnosed with a disorder across six regions. Explain one issue that limits the interpretation of the data. [3 marks]
1 What it shows
The chart shows the share of diagnoses in each region, with one region far higher than the rest.
2 The limitation
The figures are diagnosis rates, not prevalence, and diagnosis depends on access to services, awareness and stigma, which differ by region.
3 So what
A high figure may show that the disorder is reported more often there rather than that it is genuinely more common, so the chart may lack validity as a measure of true prevalence.
A validity point, precisely madeDo not speculate about why one region is higher. Use what the chart can and cannot show.
💡 Exam tip
Use the correct term for the problem: validity, reliability, causation, generalisability. Precision reads as competence.
Write no more than four sentences. Then move on.
Look at the axes first. Missing units, undefined scales and uneven time intervals are the fastest limitations to find.
Do not offer explanations for the data. That is inventing information the source does not contain.
Keep to eight minutes so Q4 keeps its full 45.
⚠ Common mix-up
Giving two or three limitations. Only the first is credited and the rest cost time.
Listing strengths. The question asks what limits interpretation.
Inventing data. If it is not in the chart, it is not evidence.
Stopping after naming the problem. The consequence is the third mark.
Bringing Source 1 into the essay. It is for Q1 only.
Up next: Paper 3, Question 2: What to Write — six marks for analysing findings and reaching a conclusion linked to the claim.
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