Quartet Statistics¶

Lesson Goal:¶

Students calculate measures of centrality and dispersion from a sample of countries.

Time Frame:¶

60’

Key Concepts:¶

Types of Variables: category, ordinal, scalar, datetime, discrete, continuous
Measures of Centrality: mean, median, mode
Measures of Dispersion: range, standard deviation, quartiles

Trump Quartets¶

A trump quartet can be used in a variety of ways in statistics lessons. Small groups can draw cards, summarise them, calculate measuers, enter data, discuss sampling etc. I got hold of a deck with European countries for my lessons, as I find these more interesting than the race cars or dinosaurs, which are common in the shops.

I have never played the actual trumps game in class, but the cards have proven an extremely cost-efficient teaching tool.

Warm-up: Guess the Country¶

Share a country card to 5-10 small groups or pairs of students. Take one yourself. Explain something about the country on your card. Use information on the card, and others

The group has to guess which country it is. Then the next persons draws two cards and picks one.

Play a few rounds.

Lesson Plan¶

Most groups already know several of the metrics. However, many will lack detail (e.g. the precise definition of the standard deviation. The purpose of this lesson is to structure core concepts and to do practical exercises with them.

This lesson is also a good opportunity to practise data entry and calculationss in a tool of your choice.

step	description	time
	distribute at least 10 quartet cards among the students	1’
	write the values for one variable (e.g. population) on the board or a spreadsheet	10’
	ask how one could summarize the data. Present the centrality metrics one by one. Perform the calculations	10’
	add or remove an outlier and discuss its effect	5’
	Do the same for the dispersion metrics	15’
	discuss the reflection questions	10’
	optional: display some of the data as a bar plot or box plot	15’

Comments¶

The tasks can be implemented perfectly in a spreadsheet application. You might also use a Google Spreadsheet (add screenshot). Also, a programming language like Python or a database should work.

Make the data entry a collaborative exercise! It will help you to balance the pace.

Reflection questions¶

what is the difference between mean and median?
what effect do outliers (e.g. Malta) have on the measures?
is it important whether a card contains integers or floating point numbers?