Entry 13Wheel of aptitude: visualizing student distributions and flows shown in a 3-dimensional cascade diagram
Youngju Oh, Seokyeol Kim, and Jinah Park — Korea Advanced Institute of Science and Technology

Many students have a hard time finding their aptitude before entering college, so they may change their majors after entering college. To gain some insights on characteristics of the students who are interested in one major compare to the others, for each selected major, I arranged the population of students in a stack according to their ACT score, and made cascade diagrams for showing how many students are remained in the selected major on the next stage.

There are 3 stages for the students to declare their major of study: T1, T2, and T3. These time lines are represented as 3 layers going from top to bottom in order. For each layer, all 18 majors are arranged in circle, where each major was shown as a tower of cylinders. The shades of each cylinder represent the ACT score levels, where brighter in color for higher score. Both radius and height of each cylinder are proportional to the number of students. Therefore by comparing the height and the distribution of the shades of the tower, we can easily observe the characteristics of the students in each group.

The influx and outflux of each major were represented by lines, which link the majors chosen in two consecutive stages. The color of each line represents the major selected at the later stage, and the thickness of each line is proportional to the percentage of students in the earlier stage who move to the certain major at the next stage. The vertical fall lines are for the flow into the same subject, while the horizontal spreads are the flows into the other subjects.

By displaying the student characteristics encoded in cylinders together with the student flows by lines in 3D, we can combine the information and extract some information that may not be obvious from either one of them alone. If we see “Eng. Tech. & Drafting”, for example, the lines heading itself is relatively thin, and the brighter circle becomes smaller on T2. Thus we can speculate that the students with higher ACT score tend to leave for the other majors from “Eng. Tech. & Drafting” major.

Youngju Oh, Seokyeol Kim, and Jinah Park

School of Computing,
Korea Advanced Institute of Science and Technology,
291 Daehak-ro, Yuseong-gu, Daejeon, Republic of Korea

{pizzing, sy.kim, jinahpark}@kaist.ac.kr