Single measurement variables
Students can measure and represent data collected about themselves.
They can then be asked to speculate about whether these measurements would represent a larger population (such as all students in their year across Australia) leading to an informal inference.
This relies on careful definitions of the sample and population, appreciating the most appropriate graphical representation, and knowing which measures of centre and spread will summarise the sample data.
Using this evidence to make an informal inference, students must realise that their conclusion cannot be made with absolute certainty because of the gap between their sample and the population.
Students might collect data on
- how long they can balance on one foot with their eyes closed
- the length of their written signature
- the length of their arm span (see Building Informal Inference with TinkerPlots in a Measurement Context).
Balancing act 1
Results from class investigations about balancing on one foot are used to make inferences about different groups or larger populations.
Signature length 1
Data collected from class investigations about signature lengths are used to make predictions about larger populations.
This investigation uses a tag-release-recapture method to estimate the number of paperclips in a container. The resource includes a student worksheet, video clip and student work sample.