The Statistical Enquiry Cycle
Master The Statistical Enquiry Cycle for GCSE Statistics with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA and Edexcel. The statistical enquiry cycle runs through planning, collecting, processing, representing, analysing and interpreting data to answer a question.
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These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA and Edexcel specifications. Every worksheet comes with a full mark scheme.
Topic overview
The statistical enquiry cycle is the process statisticians follow to answer a question using data. It gives structure to an investigation and is the framework the whole course sits within.
The cycle has four stages. Plan the investigation, including writing a hypothesis and deciding what data to collect. Collect the data using a suitable method. Process and represent the data using tables, calculations and diagrams. Interpret the results and evaluate how well the method worked.
It is called a cycle because evaluation often leads back to planning. If the results are unclear or the method had weaknesses, the investigation is refined and run again. Questions frequently ask you to name the stage that comes before or after another, so learning the order matters.
Revision notes
The four stages
1. Plan: write a hypothesis, decide what data is needed and how to collect it.
2. Collect: gather the data using the chosen method. 3. Process and represent: calculate statistics and draw diagrams. 4. Interpret and evaluate: draw conclusions and assess the method.
Why it is a cycle
Evaluation often reveals problems — a biased sample, an ambiguous question, or too small a sample size.
The investigation is then refined and repeated, returning to the planning stage. This is why it is drawn as a cycle rather than a straight line.
What examiners ask
Naming a stage, or identifying which stage comes before or after another.
Also identifying which stage a described activity belongs to. Writing a hypothesis is planning; drawing a histogram is processing and representing; saying whether the hypothesis was supported is interpreting.
Key points
- Plan the investigation and write a hypothesis.
- Collect the data using a suitable method.
- Process and represent the data using tables and charts.
- Interpret the results and evaluate the method.
- Evaluation can lead back to planning.
- It is a cycle, not a straight line.
Worked examples
Example 1
Name the stage of the statistical enquiry cycle that comes immediately before interpreting the results. [1 mark]
Working
Example 2
A student draws a scatter diagram of their results. State which stage of the cycle this belongs to. [1 mark]
Working
Example 3
Explain why the statistical enquiry cycle is drawn as a cycle. [2 marks]
Working
Common mistakes
Getting the stages in the wrong order.
Plan, collect, process and represent, interpret and evaluate.
Treating it as a straight line.
Evaluation leads back to planning, which is why it is a cycle.
Confusing processing with interpreting.
Processing produces the diagrams and calculations; interpreting draws conclusions from them.
Forgetting the hypothesis is part of planning.
Writing the hypothesis comes at the planning stage.
Exam tips
- Learn the four stages in order.
- Match described activities to the correct stage.
- Explain the cycle through evaluation leading back to planning.
- Use the exact stage names from the specification.
Key terms
- Statistical enquiry cycle
- The four-stage process for answering a question with data.
- Hypothesis
- A statement to be tested by the investigation.
- Interpret
- To draw conclusions from processed data.
- Evaluate
- To assess how well the method worked.
Related topics
Written and reviewed against the current AQA and Edexcel specifications. Spotted an error? Let us know.