Chapter 5 Chi-squares

While many of the things we are interested in when it comes to psychological research are continuously distributed (height, weight, reaction time, personality), there are many instances where we will need to work with data that is categorical. This can involve categorical independent variables (e.g. assigning participants to one or two groups) or categorical outcomes (e.g. responding yes or no). We’ll start with looking at relationships between these categorical variables, and testing for significant associations.

This module will see you diving deep into Jamovi again - so be prepared to get hands on with a bunch of data! Between the seminar, the worked examples and exercises there are at least 6 different datasets to play around with for this week!

By the end of this module you should be able to:

• Describe how a chi-square statistic is calculated
• Conduct two forms of chi-square tests: goodness-of-fit and tests of independence
• Calculate and interpret an appropriate effect size for tests of independence

Figure 5.1: xkcd: Question