Suppose you are interested in the causal effect of taking a test prep course on a student's SAT

score. (The SAT is a test which is often used by universities in the U.S. to help determine

admission decisions.) The following table shows the potential SAT scores for Amanda and Filipe

if they had taken the course and if they had not taken the course. denotes the actual SAT score

for person , is an indicator for whether person took the course, and the potential outcome notation is the same as used in the class notes.