In this lesson, we will cover ways of examining an association between two categorical variables.

As an example, we’ll explore a sample of data from the Narcissistic Personality Inventory (NPI-40), a personality test with 40 questions about personal preferences and self-view. There are two possible responses to each question. The sample we’ll be working with contains responses to the following:

• influence: yes = I have a natural talent for influencing people; no = I am not good at influencing people.
• blend_in: yes = I prefer to blend in with the crowd; no = I like to be the center of attention.
• special: yes = I think I am a special person; no = I am no better or worse than most people.
• leader: yes = I see myself as a good leader; no = I am not sure if I would make a good leader.
• authority: yes = I like to have authority over other people; no = I don’t mind following orders.

As you might guess, responses to some of these questions are associated. For example, if we know whether someone views themself as a good leader, we may also find that they’re more likely to like having authority. In this lesson we’ll learn how to assess whether an association exists between any two of these variables.