The x-axis is organized by the year in which a given course is typically taken. The year typically taken is determined by the year in the academic career during which most students take the course, also known as the mode year. The Course Explorer is organized by the year of the academic career, with each year distinguished by color. The number of years included in the display will vary by institution.
In this example, all of the purple bubbles represent courses that are typically taken during the third year of the student’s academic career that show the strongest signal of students’ individual graduation likelihoods.