The case study was designed to allow the College Board to quickly test a student's knowledge of object oriented programming ideas such as inheritance and encapsulation while requiring students to understand how objects such as "the environment", "the fish", and the simulation's control module interact with each other without having to develop the entire environment independently, which would be quite time-consuming. The case study also gives all students taking the AP Computer Science exams with a common experience from which to draw additional test questions.