<P> On each of the exams, at least one free - response question was derived from the case study . There were also five multiple - choice questions that are derived from the case study . </P> <P> This case study was discontinued from 2007, and was replaced by GridWorld . </P> <P> GridWorld is a computer program case study written in Java that was used with the AP Computer Science program from 2008 to 2014 . It serves as an example of object - oriented programming (OOP). GridWorld succeeded the Marine Biology Simulation Case Study, which was used from 2000--2007 . The GridWorld framework was designed and implemented by Cay Horstmann, based on the Marine Biology Simulation Case Study . The narrative was produced by Chris Nevison and Barbara Cloud Wells, Colgate University . </P> <P> The GridWorld Case Study was used as a substitute for writing a single large program as a culminating project . Due to obvious time restraints during the exam, the GridWorld Case Study was provided by the College Board to students prior to the exam . Students were expected to be familiar with the classes and interfaces (and how they interact) before taking the exam . The case study was divided into five sections, the last of which was only tested on the AB exam . Roughly five multiple - choice questions in Section I were devoted to the GridWorld Case Study, and it was the topic of one free response question in Section II . </P>

When is the last time for the gridworld case study to be tested