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AP Computer Science Principles (College Board): complete guide to the five Big Ideas, the computational thinking practices, the AP CSP pseudocode, the Create performance task and the end-of-course exam

A complete guide to College Board AP Computer Science Principles. Covers the five Big Ideas (Creative Development, Data, Algorithms and Programming, Computer Systems and Networks, and Impact of Computing), the computational thinking practices, the AP CSP pseudocode reference, how the Create performance task and the end-of-course multiple-choice exam work, and how to study each Big Idea for a 5.

Browse guides →Syllabus dot points (28)

College Board AP Computer Science Principles is a broad, introductory course that explores the whole field of computing: how programs are created, how data is represented and processed, how algorithms and programming work, how computer systems and networks (like the Internet) move data, and how computing affects society. It is language-agnostic, using the College Board's AP CSP pseudocode for the exam, and it is assessed in two parts: the Create performance task (a program you develop and document) and an end-of-course multiple-choice exam. This page is the index: below is a map of the five Big Ideas, the assessment, and how to study.

The five Big Ideas

The College Board organizes the content into five Big Ideas that run throughout the course.

Big Idea 1 Creative Development
Collaboration and diverse perspectives, what a program's purpose and function are, the iterative development process, and identifying and correcting the different types of program errors.
Big Idea 2 Data
How all data is represented in binary, data compression (lossless and lossy), extracting information from data (and that correlation is not causation), and using programs to process large data sets.
Big Idea 3 Algorithms and Programming
Variables and assignment, mathematical and Boolean expressions, conditionals and nested conditionals, iteration, lists, data and procedural abstraction, developing algorithms, procedures and libraries, binary search and algorithmic efficiency, simulations and random values, and undecidable problems.
Big Idea 4 Computer Systems and Networks
How the Internet works (addressing, packets, protocols), fault tolerance through redundancy, and parallel and distributed computing.
Big Idea 5 Impact of Computing
The beneficial and harmful effects of computing innovations, the digital divide, computing bias, crowdsourcing, legal and ethical concerns (intellectual property and privacy), and safe computing.

Assessment structure

AP Computer Science Principles is assessed in two components that combine into the 1 to 5 score.

  • Create performance task - 30%. You design and develop a program, then submit your program code, a video of it running, and written responses describing its purpose and function, your development process, a chosen algorithm and procedure, and your testing.
  • End-of-course exam, multiple choice - 70%. About 70 questions in 2 hours, drawing on all five Big Ideas. Questions mix reading and writing AP CSP pseudocode with reasoning about data, systems and the impact of computing.

The questions are written from the computational thinking practices (solution design, algorithm and program development, abstraction, code analysis, analyzing computing innovations, and responsible computing), so you must reason about code, data, systems and society.

The AP CSP pseudocode

The exam uses a College Board pseudocode reference sheet, provided on exam day, instead of a specific language. The essentials:

  • Assignment: a ← expression evaluates the right side first, then stores it in a.
  • Output and input: DISPLAY(expr) and INPUT().
  • Arithmetic: + - * / and MOD (the remainder).
  • Boolean: relational operators and the logical operators AND, OR, NOT.
  • Selection: IF (condition) { ... } ELSE { ... }.
  • Iteration: REPEAT n TIMES { ... } and REPEAT UNTIL (condition) { ... }.
  • Lists: 1-indexed, with list[i], APPEND, INSERT, REMOVE, LENGTH, and FOR EACH item IN list.
  • Procedures: PROCEDURE name(params) { ... RETURN value }, and RANDOM(a, b) for a random integer in an inclusive range.

How to study AP Computer Science Principles

AP CSP rewards both confident pseudocode reasoning and clear analysis of data, systems and impact.

  1. Work from the Course and Exam Description. Each topic (for example 3.8 Iteration) maps to learning objectives and essential knowledge statements that exam questions are written from.
  2. Read and trace pseudocode by hand. Many multiple-choice questions show a code segment and ask what it does. Track each variable one statement at a time.
  3. Master the pseudocode reference. Know assignment, MOD, the Boolean operators, the loop forms, and the 1-indexed list operations cold.
  4. Practice the Create task skills. Be ready to describe a program's purpose and function, your iterative development and testing, and a selected algorithm and procedure, with proper attribution of any borrowed material.
  5. Reason about impact. For Big Ideas 4 and 5, practice giving balanced, specific analyzes: both benefits and harms, intended and unintended effects.

The Big Ideas, topic by topic

Each topic has a Course-and-Exam-Description-level answer page with worked exam questions and cross-links, plus an overview guide and quiz. Browse the set at /ap/computer-science-principles/syllabus.

For the official Course and Exam Description

The College Board publishes the full Course and Exam Description, the AP CSP exam reference sheet, the Create performance task requirements and scoring guidelines at apcentral.collegeboard.org. Always study from the current Course and Exam Description and the College Board's own released materials, because the pseudocode, the Create task requirements and the exam weighting are board-specific.

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Common questions about Computer Science Principles

How is AP Computer Science Principles structured?
AP Computer Science Principles is a broad, conceptual, introductory computing course organized into five Big Ideas: Big Idea 1 Creative Development (collaboration and the development process), Big Idea 2 Data (binary, compression and extracting information), Big Idea 3 Algorithms and Programming (variables, conditionals, iteration, lists, procedures, efficiency), Big Idea 4 Computer Systems and Networks (the Internet, fault tolerance, parallel computing), and Big Idea 5 Impact of Computing (benefits and harms, the digital divide, bias, crowdsourcing, ethics and safe computing). The course is language-agnostic and uses the College Board's AP CSP pseudocode for the exam.
How is AP Computer Science Principles scored?
The AP CSP score combines two components. The Create performance task is worth 30% of the score: students develop a program over class time and submit their program code, a video of it running, and written responses. The end-of-course exam is worth 70%: it is a multiple-choice exam of about 70 questions in 2 hours, drawing on all five Big Ideas. The two combine into the 1 to 5 AP score. Always confirm the current weighting and question count against the official Course and Exam Description.
What is the AP CSP pseudocode?
The AP CSP exam uses a College Board pseudocode (the exam reference sheet) rather than a specific language like Java or Python, so the exam is language-agnostic. Its key features are the arrow for assignment (a gets expression), DISPLAY and INPUT for output and input, MOD for the remainder, the logical operators AND, OR and NOT, IF and ELSE for selection, REPEAT n TIMES and REPEAT UNTIL for iteration, 1-indexed lists with APPEND, INSERT, REMOVE and LENGTH, FOR EACH for traversal, and PROCEDURE with RETURN for procedures. The reference sheet is provided on exam day.
What is the Create performance task?
The Create performance task is the through-course assessment worth 30% of the AP CSP score. Students design and develop a program of their own choosing, then submit three things: the program code, a short video demonstrating the program running (including input and output), and written responses describing the program's purpose and function, how they developed it (including a difficulty and how collaboration or iteration resolved it), a selected algorithm and procedure, and how they tested it. Any borrowed code or media must be properly licensed and attributed.
What are the computational thinking practices in AP CSP?
The Course and Exam Description defines computational thinking practices that the questions are written from: Computational Solution Design, Algorithms and Program Development, Abstraction in Program Development, Code Analysis, Computing Innovations (analyzing impact), and Responsible Computing (collaboration, ethics and documentation). The Create task and the multiple-choice exam are both built on these practices, which is why the exam mixes writing and reading pseudocode with reasoning about data, systems and the impact of computing.
How does AP Computer Science Principles compare to AP Computer Science A?
AP Computer Science Principles is broader and more conceptual, language-agnostic, and covers the whole field of computing including data, the Internet and the impact of computing, with the Create performance task as a portfolio component. AP Computer Science A is a deeper, Java-based programming course equivalent to a first-semester college course for computing majors, focused on object-oriented design and data structures. CSP is the wider survey; CS A is the deeper programming course. Always study from the current Course and Exam Description for whichever you take.