A scatterplot shows that the more hours students spend making notes on a phone, the lower their test marks. It looks like an open-and-shut case. It is not — and knowing exactly why is worth several marks in Paper 3.
📚 What you need to know
A scatterplot shows the relationship between two co-variables — here, hours of note-taking on a phone and marks in a class test.
Describe three things: direction (positive or negative), strength (how tightly the points hug the line) and outliers.
A downward pattern is a negative relationship: as one variable rises, the other falls.
A few outliers do not destroy a trend, but they must be mentioned.
Correlational data cannot establish cause, so “phones impede learning” goes beyond the evidence.
A plausible mechanism is depth of processing: typing quickly encourages copying word for word, while summarising forces you to understand.
Reverse causation and third variables must always be offered before you conclude.
Reading a scatterplot properly
The red point is a heavy phone user with a high score. One case like this weakens a claim without destroying the trend.
🧩 Describing a scatterplot in four sentences
Name the co-variables. “The co-variables are hours of note-taking on a phone and marks in a class test.”
Give the direction. As hours rise, marks fall — a negative relationship.
Give the strength. The points cluster fairly tightly around the line, so the relationship is reasonably strong.
Mention outliers. A few cases do not follow the trend, but not enough to remove it.
Say “co-variables”, not “independent and dependent variables”. In a correlation nothing is manipulated, so there is no IV. Using the right word here is a quiet signal that you understand what kind of study you are looking at.
Why the relationship might exist
The graph shows a pattern. Psychology’s job is to suggest a mechanism — and then to test it, which the graph cannot do.
Depth of processing
When you type, you can go fast enough to copy words down almost exactly as they are said. When you write by hand, or summarise, you cannot keep up, so you are forced to decide what matters and put it in your own words. That decision is the learning. Research comparing handwritten and typed notes has repeatedly found that verbatim copying predicts weaker understanding later, even when the notes themselves are complete.
The principle
effort at encoding → deeper processing → better recall later
Distraction
A phone is not only a notepad. Every notification arrives on the same device, so note-taking on a phone means repeatedly switching attention away from the lesson and back again. Each switch has a cost, and the material missed during the switch is never encoded at all.
Three explanations for one correlation
Before you accept that phones damage learning, you have to rule out two other stories — and this graph cannot rule out either.
Story 2 is the one students forget: a student already struggling may reach for the fastest method available.
How you would actually test it. Randomly assign students to take notes by phone or by hand on the same lesson, then test them a week later. Random allocation removes the third-variable problem, which is exactly what the scatterplot cannot do.
Worked examples
WORKED EXAMPLE
Analyse the findings from this source and state a conclusion based on them. [6 marks]
Describe the data
The data is presented as a scatterplot in which the co-variables are the number of hours spent making notes on a smartphone and the marks awarded in a class test. The pattern slopes downward, so as hours of phone note-taking increase, test marks tend to decrease. The points sit fairly close to the line of best fit, indicating a reasonably strong negative relationship, and although there are a small number of outliers they are not numerous enough to remove the overall trend.
Interpret it
One explanation is depth of processing: typing quickly on a phone allows a student to record words without deciding what they mean, whereas summarising forces the material to be processed more deeply. A second is distraction, since notifications arrive on the same device and repeated attention switching means some of the lesson is never encoded.
Conclusion, with a caution
The findings suggest that making class notes on a smartphone is associated with lower test performance. However, because this is correlational data, cause and effect cannot be established: students who are already struggling may be more likely to choose the quickest method, and a third variable such as general attention or motivation could produce both results. The conclusion should therefore be that the two are related, not that phone note-taking impedes learning.
WORKED EXAMPLE
Explain one limitation linked to the interpretation of this scatterplot. [3 marks]
Point
The scatterplot shows a correlation, so the direction of the relationship is unknown.
Explain
It is equally consistent with the data that students who are already performing poorly turn to the fastest note-taking method available, rather than that the method lowered their marks.
Link
This means the claim that phone note-taking impedes learning cannot be supported by this source, and only an experiment with random allocation could separate the two possibilities.
💡 Exam tip
Always use the word co-variables when describing a correlation. It is precise and it takes one second.
Give direction and strength separately. “Negative” and “fairly strong” are two different pieces of information.
Mention outliers, then weigh them. Saying they exist but do not overturn the trend is a mature judgement.
Offer a mechanism. Depth of processing and distraction are both credible and both easy to explain.
Give the reverse direction explicitly. Do not just say “correlation is not causation” — show the alternative.
Say what study would settle it. Random allocation to note-taking method, tested a week later.
⚠ Common mix-up
Calling the hours an independent variable. Nothing was manipulated, so there is no IV.
Reading “negative” as “weak”. Negative describes direction; strength is about how tightly the points cluster.
Ignoring the outliers because they are inconvenient. Mentioning them earns credit.
Concluding that phones harm learning. The data allows an association, nothing more.
Assuming handwriting is always better. The benefit comes from summarising, and you can summarise on a device.
Inventing sample details. The plot shows dots, not who the students were.
Up next: What Technology Does to Memory — the google effect, and the strange discovery that we now remember where things are instead of what they say.
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