The Statistical Enquiry Cycle - All Five Stages
Follow a statistical investigation through all five stages of the enquiry cycle, from the first question to the final review, and learn the key terms along the way.
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The statistical enquiry cycle
Statisticians do not just crunch numbers. They follow a clear process called the statistical enquiry cycle, or SEC. It has five stages, and it is a cycle, so after evaluating you can go back and improve. This module walks through all five stages, from the first question to the final review.
The five stages
Every statistical investigation moves through these five stages, in order:
Primary or secondary?
In the collecting stage, data comes from one of two kinds of source:
Match the stage to its activity
- Planning
- Collecting data
- Processing and presenting
- Interpreting
- Deciding the question and what data to collect
- Gathering the data from a source
- Drawing diagrams and calculating statistics
- Analysing the results and reaching a conclusion
Which stage?
In which stage do you draw diagrams and calculate statistics?
- Processing and presenting
- Planning
- Collecting data
- Evaluating
Words you need
A few terms come up throughout the cycle. A hypothesis is a statement you set out to test, such as taller people have longer arms. Reliability is how much you can trust the findings, and results are more reliable from a larger, fairer sample. An inference is a conclusion or prediction you draw from the data.
Match the term to its meaning
- Hypothesis
- Primary data
- Secondary data
- Reliability
- A statement you set out to test
- Data you collect yourself, first-hand
- Data collected by someone else
- How much you can trust the findings
In the planning stage?
Select the TWO things you do in the PLANNING stage.
- Decide on a question or hypothesis
- Decide what data to collect and how
- Draw diagrams of the results
- Reach a conclusion about the question
Order the cycle
Put the five stages of the statistical enquiry cycle into the correct order.
- Planning: decide the question and the data
- Collecting the data
- Processing and presenting the data
- Interpreting the results
- Evaluating and reviewing
Complete the cycle
The cycle has five stages. First you do the _____, where you set a hypothesis. Then you collect the _____. Data you gather yourself is called _____ data. Near the end you reach a _____ about your question. Finally you _____ the work and suggest improvements.
The enquiry cycle
Tap the TWO statements that are TRUE.
- The statistical enquiry cycle has five stages.
- Primary data is data you collect yourself, first-hand.
- You draw diagrams during the planning stage.
- Secondary data is always more reliable than primary data.
- A hypothesis is a diagram of the results.
Which stage is it?
For each task, choose which stage of the cycle it belongs to.
- A student writes down the idea that older pupils spend more on lunch. Which stage is this?
- The student hands out a survey and records the answers. Which stage is this?
- At the end, the student notes that the sample was too small and should be larger next time. Which stage is this?
Plan an investigation
Choose a question you could investigate, such as whether taller people have larger hands, and describe how you would use the statistical enquiry cycle to answer it. This is written in English and is not auto-marked.
- State your question or hypothesis (the planning stage)
- Say what data you would collect, and whether it is primary or secondary
- Say how you would process and present the data
- Say how you would interpret and then evaluate your findings