Meaningful differences

When looking at distributions comparing two data sets, some students will declare a difference in the two groups based on only one or two data values.

For other students, there may be a reluctance to declare a difference if there is any overlap of the two distributions.

Authentic examples of misjudgements illustrate responses of younger students just beginning to compare two samples of data to make judgements about populations. These types of comments can be expected from students.

Teachers need to be prepared for further discussion, perhaps related to the mean, median or shape of the distribution. Examples related to rainfall can be found in Is There a Difference? and an activity on differences in heights is provided.

Curriculum links

Year 9: Identify everyday questions and issues involving at least one numerical and at least one categorical variable, and collect data directly from secondary sources (ACMSP228)