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Making informal inferences

Informal inference relies on students' understanding of the:

  • relationship of samples and populations
  • importance of creating the most appropriate representation of the data
  • measures that will best summarise the data set.

The evidence collected from this process is used to make a claim for the wider population within the context. Because the population is not completely known, the claim cannot be made with absolute certainty. Over time, students develop intuitions about the degree of certainty they can place on their conclusions. For some contexts this intuition about uncertainty may be assisted by box plots which are introduced in year 10.

Examples of contexts for carrying out informal inference can be found in the article Building Informal Inference with TinkerPlots in a Measurement Context.

Single measurement variables

Students can collect measurement data and make informal inferences.

Comparing two populations

It is possible to extend investigations of measurement variables to compare samples representing two different populations.

Curriculum links

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

Year 9: Compare data displays using mean, median and range to describe and interpret numerical data sets in terms of location (centre) and spread

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