This sunburst chart, also known as a multilevel pie chart, visualizes the student progression through math classes at CSUN. The inner circle depicts the first math course attempted by a student. The color denotes a particular course. Hovering over a region shows the percentage of students who attempted that the course or sequence of courses; the numbers appear in the upper left-hand corner of the page. Gray is used to show when the percent of students who terminated their studies in mathematics. Less than a quarter of all math courses are attempted by STEM majors.
Sunburst charts are an efficient way of representing hierarchical data using concentric circles. The sequence of courses attempted to finish any major is hierarchical data (freshmen, sophomore, junior, senior).