It’s very easy to think of teaching statistics in terms of the written curriculum and see it as a checklist of isolated techniques and graphs; calculate a mean, draw a pie chart, find the range and so on. But look at reports like GAISE from the US or recent curriculum developments in New Zealand and Victoria (Australia) and you will see evidence of a pattern emerging. Students aren’t studying statistics to learn about calculating standard values or drawing standard graphs, they’re doing it because understanding statistics is fundamental to understanding the world in which they live now, and the wider world in which they will soon be unceremoneously thrust once they complete their compulsory education. Stats – unbelievably – are becoming sexy.
I’m the kind of person who follows MPs and economists on Twitter and I recently came across this rather wonderful graph showing how we tax alcohol in the UK, which appeared after the recent budget.
Source: gov.uk(2016), Rates and allowances: Excise Duty – Alcohol Duty
It got me thinking: if we follow the mathematics curriculum as currently written in the UK, do we really prepare students to deal with information presented in this form?
There’s a lot going on in the Excise Duty graph which goes beyond simple mathematics and into a more socio-political sphere that might be fascinating for students to explore.
How does the tax differ depending on what type of alcohol is being purchased?
How does it change by quantity?
Why is it that as beer gets stronger the tax rate increases, but for wine and cider the opposite happens?
What does the shape of the line for beer even mean?
What’s a statistician’s favourite wine?*
A factsheet from the interestingly named “Institute of Alcohol Studies” (but be careful when citing them as a source, their research evidence only counts as 40% proof…) sheds some light on what is going on.
Due to a European directive, beer and spirits are taxed in proportion to their alcohol content, whereas wine and cider are taxed in proportion to the volume sold - this accounts for some of the interesting shapes in the graph.
Perhaps you could challenge your students to come up with a new way of taxing alcohol which takes into account health concerns and underage drinking? What would these graphs look like?
These are the kinds of charts and graphs – showing complex information – that people are exposed to on a regular (if not daily) basis. It is essential that statistics lessons stray beyond the narrow confines of standardised charts to allow students a rich, critical experience of data in contexts that are engaging.
*"Why does everyone keep inferring causation from correlation?"