To use your chosen predictors in a CART, you need to devise binary yes/no questions that query their values.
Look across your predictors and write down all the possible questions you might as about them. We’ll keep it simple and just ask “Does Predictor X have value A” type questions, and not try to form category questions such as “Is the value of Predictor X in the set {A, B, C}”
Here’s a sheet where you can write down the questions.
Video to be added after the lecture…