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# Informal inference

From the early years when students start collecting their own data, they can ask about a wider context. For example, "Would the class next door or in the next school have the same data?"

Informal inference is about moving beyond the data collected (the sample) to a larger context (a population).

The three key elements of informal inference are evidence, generalisation and degree of certainty.

• Evidence is collected from distributions that display variation and expectation from the data.
• Generalisation is the claim made beyond the data collected to a wider population.
• Degree of certainty is related to the confidence in the process carried out. Random samples and larger samples engender more confidence in a generalisation.

Over the middle years, students learn about random samples from populations, about how to display the data appropriately to provide reliable evidence, and about building intuitions for how certain they can be with their informal inferences.

## Curriculum links

Year 6: Interpret secondary data presented in digital media and elsewhere

Year 8: Explore the practicalities and implications of obtaining data through sampling using a variety of investigative processes

Year 8: Explore the variation of means and proportions of random samples drawn from the same population

Year 10: Construct and interpret box plots and use them to compare data sets

Year 10: Use scatter plots to investigate and comment on relationships between two numerical variables

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