Analysing data and drawing conclusions

Results only become useful when you spot the pattern, explain it with science, and decide what it really shows.

Practise this lesson free (7 questions)

Hypotheses and patterns

A hypothesis is an idea that explains something and can be tested, for example "enzymes work faster when warmer because particles collide more".
A prediction says what should happen if the hypothesis is right.
On a graph, look for a correlation: positive (both go up together), negative (one goes up as the other goes down) or none.
If the line is straight and goes through the origin (0, 0), the two variables are directly proportional: double one and the other doubles.

Correlation is not cause

A correlation does not prove that one thing causes the other.
Ice cream sales and sunburn both rise in summer, but ice cream does not cause sunburn: both are caused by sunny weather.
To show cause, scientists change one variable and control all the others, and look for a scientific mechanism that explains the link.

Writing a conclusion

A good conclusion:
1. Describes the pattern, using numbers from the data.
2. Explains it using scientific ideas.
3. Says whether it supports the prediction or hypothesis.
Then evaluate: how confident are you, and what further questions do the results raise?
You can also use equations: if speed = distance ÷ time, then distance = speed × time and time = distance ÷ speed.
Worked example

A spring stretches 4 cm with a 2 N force. The force and extension are directly proportional. What is the extension with 5 N?

  1. Extension per newton = 4 ÷ 2 = 2 cm per N
  2. 5 N × 2 cm per N

Answer: 10 cm

Key idea

Look for a correlation (positive, negative or none). A straight line through the origin means directly proportional. Correlation is not cause. A conclusion describes the pattern with data, explains it with science, and links back to the hypothesis.

Key words
Speed
How far something travels each second: speed = distance ÷ time, often in m/s.
Speed = distance ÷ time
speed (m/s) = distance (m) ÷ time (s). Rearranged: distance = speed × time; time = distance ÷ speed. Example: 400 m in 80 s gives 5 m/s. This is the average speed over the journey.

All KS3 Science key terms and definitions →

Common mistakes
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Extra practice

2 more questions

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  1. As the height of a ramp increases, the speed of a toy car at the bottom increases. What kind of correlation is this?

    1. Positive correlation
    2. No correlation
    3. Inverse proportion
    4. Negative correlation
    Show the answer

    Answer: Positive correlation

    Both variables increase together.

  2. When force doubles, extension doubles. What does this show?

    1. Extension is inversely proportional to force
    2. Extension is directly proportional to force
    3. Extension is always zero
    4. They are not related
    Show the answer

    Answer: Extension is directly proportional to force

    Directly proportional quantities change by the same factor.

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Sources and references

Checked by the GCSE-ready editorial team, 17 October 2026. Last updated 2 October 2026. Spotted a mistake? Tell us and we will fix it.