Where AP CSP begins. Learn how programs are created to serve a purpose, how collaboration and an iterative development process make them better, and how to identify and correct the errors that inevitably appear along the way.
Six ways to master Unit 1 — pick whichever fits how you like to study.
All 4 topics from the College Board CED, in order.
Unit 1 covers Big Idea 1: Creative Development, the foundation for building programs in AP CSP. It begins with collaboration — programs are usually created by teams, and diverse perspectives lead to better, more inclusive software while helping catch mistakes early. You'll learn to describe a program's function (what it does) and its purpose (why it exists and who it serves), along with the inputs it receives and the outputs it produces.
The unit then develops the iterative and incremental development process: investigating and reflecting, designing, prototyping, and testing — repeating the cycle and using feedback to improve. Finally, it addresses the reality that programs contain errors, teaching you to identify logic, syntax, run-time, and overflow errors and to correct them through testing and debugging.
This is Big Idea 1, worth 10–13% of the multiple-choice exam. The six computational thinking practices below spiral through this and every big idea: