The Statistical Enquiry Cycle - All Five Stages

The Statistical Enquiry Cycle 🔄

Every statistics investigation, from a school survey to national research, follows the same **five-stage cycle**. It underpins every paper you will sit. The stages are: **planning**, **collecting**, **processing and representing**, **interpreting**, and **evaluating**, which loops you back to a new question. Learn the loop and you can tackle anything.

The five stages

An interactive activity.

Match each stage to its main activity

Stage 1: Initial planning 📝

Everything starts with a clear **question or hypothesis**. Then you decide **what data to collect and how**, and plan how you will process and represent it. The examiner wants **reasons** for every choice: why this data, why this sampling method, why this kind of chart. Planning well makes the whole enquiry stronger.

Planning well

Select ALL THREE things that belong in Stage 1, initial planning.

• Defining a clear question or hypothesis
• Deciding what data to collect and how
• Giving reasons for those choices
• Drawing the final graphs
• Writing the conclusion
• Judging the reliability of the results

Stage 2: Collecting data 📥

Data comes in two kinds: - **Primary data**: data you collect yourself (surveys, experiments, observation). - **Secondary data**: data already collected by someone else (publications, the internet, the media). You must **acknowledge your sources**, and recognise **constraints** such as availability, sampling, and the sensitivity of the topic.

Primary or secondary?

You hand out your own questionnaire and collect the responses yourself. What kind of data is this?

• Primary data, because you collected it yourself
• Secondary data
• Not really data at all
• A hypothesis

Naming your sources

When you use figures from a government website, why must you acknowledge the source?

• To be honest about where the data came from and let others check it
• Only to make the report longer
• It is optional and does not matter
• To hide where the data came from

Stages 3 and 4 📊

In **Stage 3, processing and representing**, you organise the data (often with technology), draw **diagrams** and calculate **statistical measures** like the mean. In **Stage 4, interpreting**, you analyse those diagrams and calculations **in context**, reach **conclusions** about your original question, make **inferences or predictions**, and discuss how **reliable** the findings are.

Place the activity

Drawing a bar chart and working out the mean of your data happens in which stage?

• Stage 3: processing and representing
• Stage 1: initial planning
• Stage 2: collecting data
• Stage 5: evaluating

A strong conclusion

When you reach a conclusion in Stage 4, what must you do to gain full marks?

• Refer back to the original question and discuss how reliable the findings are
• Just state a single number
• Ignore the original question
• Only draw another graph

A real enquiry

An interactive activity.

Match each term to its meaning

The cycle in a nutshell

Select ALL THREE statements about the statistical enquiry cycle that are TRUE.

• The cycle repeats: evaluating leads to a new question
• You should give reasons for your data choices
• Conclusions should refer to the original question
• Primary data is always taken from the internet
• The cycle has only two stages
• The reliability of findings does not matter

Stage 5: Evaluating and looping ♻️

The final stage is to **evaluate** the whole enquiry: how reliable were the results, what were the limitations, and how could it be improved? That evaluation usually **refines the question** and sends you back to Stage 1. That is why it is a **cycle**: good statistics keeps improving.

Cycle summary

The statistical enquiry cycle has five stages: planning, collecting, processing and representing, _____, and evaluating. Data you collect yourself is _____ data, while data from elsewhere is _____ data. Good conclusions refer back to the original question and discuss their _____.