If you have a nominal variable that has more than two levels, you need to create multiple dummy variables to take the place of the original nominal variable. For example, imagine that you wanted to predict depression from year in school: freshman, sophomore, junior, or senior.
Washington Post, Redskinsâ Kirk Cousins played a round of golf with President Trump, June 14, 2017. The Hill, Trump plays 18 holes of golf at Virginia club, June 25, 2017. Washington Post, Trump had a terrible July, but at least he played a lot of golf, July 31, 2017. Washington Post, Trump seen at his N.J. golf course, Aug. 7, 2017
By comparison, Bush played 24 rounds of golf through the first 34 months of his presidency, according to CBS News, but stopped in 2003 because he didnât want to be seen by the country as a leader who took the nation being at war lightly.