AP Computer Science Principles
About this free AP Computer Science Principles course
This free AP Computer Science Principles course is a study guide and review for the AP CSP exam. It breaks down the course and exam in a straightforward, student-friendly way, walking through the College Board's five Big Ideas: Creative Development, Data, Algorithms and Programming, Computer Systems and Networks, and Impact of Computing.
Each Big Idea makes up a specific percentage of the multiple-choice section, so the course shows you where to focus your study time. Vocabulary checkpoints at the end of each unit help you check what you know. The final unit covers the Create Performance Task, the hands-on project where you develop a program and explain your design decisions. It explains exactly what you need to do, how it's graded, and how to avoid the mistakes that cost students points. Whether you're just starting the course or reviewing for the exam, it's designed to help you navigate AP CSP with confidence.
Who this course is for
This course is for high school students in grades 9 through 12 who are taking AP Computer Science Principles, preparing to self-study for the exam, or simply curious about how computers and the internet work. No programming experience is required, since AP CSP is designed as an introductory course.
Course outline
- Unit 0: Course and exam overview. How the exam is structured, how each Big Idea is weighted, and what the Create Performance Task involves.
- Big Idea 1: Creative Development. Collaboration, program design, and the development process.
- Big Idea 2: Data. Binary numbers and converting between number systems, data compression, and extracting information from data.
- Big Idea 3: Algorithms and Programming. Variables, lists and strings, algorithmic efficiency, linear vs. binary search, simulations and random events, and a debugging clinic.
- Big Idea 4: Computer Systems and Networks. Layers of the internet, packets, IP and DNS, fault tolerance and redundancy, parallel and distributed computing, and cybersecurity basics.
- Big Idea 5: Impact of Computing. The digital divide and accessibility, privacy and legal issues, computing bias, and environmental impacts.
- Unit 6: Create Performance Task. The PT timeline, a rubric deep dive, tips for success, and common pitfalls to avoid.
What you'll learn
- Explain all five AP CSP Big Ideas and their key vocabulary
- Convert between binary and decimal and reason about data representation
- Compare algorithms, including linear and binary search, by efficiency
- Describe how the internet routes data and how systems stay fault tolerant
- Plan a Create Performance Task that meets every rubric row
How long it takes
Budget about 15 hours to work through all six units and the vocabulary checkpoints. If you're reviewing for the exam in May, spreading the units across four to six weeks works well.
Frequently asked questions about AP Computer Science Principles
Is AP Computer Science Principles really free?
Yes. AP Computer Science Principles is completely free, with no fees, subscriptions, or account required. STEM for Others is a 501(c)(3) nonprofit, and every course in our curriculum library is free for students, families, and teachers.
Is this the official AP course?
No. This is an independent, student-created review course by STEM for Others volunteers. It follows the published AP CSP Big Ideas, but it isn't endorsed by the College Board. Use it alongside your class and official College Board materials.
Does it cover the Create Performance Task?
Yes. A full unit covers the Create PT: the timeline, what each rubric row is looking for, and common pitfalls that cost students points.
How do I start the course?
Click Begin Course at the top of this page to open the full slide deck in a new tab. You can also flip through the slides embedded above. Work through one unit at a time and try the practice questions before moving on.
Do I get a certificate?
The self-paced AP Computer Science Principles materials don't include an official certificate. If you're taking the course through a STEM for Others chapter program, ask your chapter leader about recognizing your completion.
Can teachers and clubs use this curriculum?
Yes. Teachers, homeschool families, libraries, and after-school clubs are welcome to use the AP Computer Science Principles materials with their students at no cost. STEM for Others volunteers also teach our curriculum in partner schools and libraries. You can find a chapter near you or start one at your school.
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