Chapter 5: Variables and Manipulation

Links to a carefully curated collection of Youtube videos provide a host of additional sourcs for you to develop your ability to use R software in an engaging and accessible manner.

Video 5.1: ‘Intro to statistics with R – types of variables’

Question 1: What are the four types of variables discussed in the video?

Answer: Nominal, ordinal, interval, and ratio

Question 2: What is the difference between interval and ratio variables?

Answer: Ratio variables have a ‘true zero point’, meaning the attribute does not exist.


Video 5.2: ‘Dummy variables or indicator variables’

Question 1: What is the difference between dummy and indicator variables?

Answer: There is no difference, they are the same thing.

Question 2: How many dummy variables do you need to need create (if using a regression model) if the original variable has more than 2 values?

Answer: If J = the number of values of the original variable, you need to create J–1 dummy variables.