Mini-course 7: Taking Out Effects - Smokers

This mini-course from the Nuffield Exploratory Data Skills Project: Making Sense of Data is about interpreting and analysing two-way tables. As a result of this mini-course students should learn to:

• look for effects in a two-way table

• look for effects in a simple display

• understand what is meant by 'additive effects'

• carry out a 'PLUS' analysis by taking out medians or by taking out means

• understand the difference between using medians and using means for a PLUS analysis

• interpret the effects and residuals from a PLUS analysis

• construct and interpret a two-way display

• consider whether a PLUS or a TIMES analysis is more appropriate

• carry out a TIMES analysis by dividing by medians

• carry out a TIMES analysis by taking logs and carrying out a PLUS analysis

• interpret the effects and residuals from a TIMES analysis

The mini-course consists of six units:

Young smokers is helpful as an introduction to the later units. 

The changing habits of young smokers explains how to carry out a median analysis, and follows on from the previous unit.

Smoking amongst adults introduces a means analysis, and compares it with the median analysis of the previous unit.

Looking again at young smokers follows on from previous work, with a display being drawn of the median analysis.

Who buys tobacco? introduces a TIMES analysis by dividing by medians.

Spending across the country shows that a TIMES analysis is the same as a PLUS analysis using logs.

The teacher guide gives an overview of the mini-course.