CONTINGENCY TABLES AND CHI-SQUARED TESTS

In this type of analysis we have two characteristics, such as gender and eye colour, which

cannot be measured but which can be used to group people by variations within them.

These characteristics may, or may not, be associated in some way. How can we decide?

We can take a random sample from the population, note which variation of each

characteristic is appropriate for each case and then cross-tabulate the data. It is then

analysed in order to see if the proportions of each characteristic in the sub-samples are the

same as the overall proportions - easier to do than describe! As an example, if there is no

relationship between gender and eye colour we would expect similar proportions of males

and females to have blue eyes.

The Variables

If the...