What’s on the AP CSP Exam: Every Topic, Explained (2025–2026)

Last reviewed: March 2026 — reflects the official College Board AP Computer Science Principles Course and Exam Description (CED), effective Fall 2023.

The AP Computer Science Principles exam tests five Big Ideas across 70 MCQ questions. There is also a Create Performance Task worth 30% of your score that is submitted before the exam date. This page translates every CED section into plain English — what it means, what the exam asks, and the trap most students fall into.

Use this as your master reference. Every topic listed is fair game for the May 14, 2026 exam. The exam uses its own pseudocode language — not Java, Python, or any specific language — so the concepts matter more than syntax.

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Big Idea 1 is about how programs are made — not the code itself, but the process of designing, building, and fixing software. The exam tests whether you understand the development lifecycle and the role of collaboration and testing.

Full reference: Big Idea 1 Study Guide

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Big Idea 2 covers how data is represented, stored, and used. Binary representation is the foundation. Data compression, metadata, and privacy implications are all tested. This big idea overlaps with real-world scenarios the exam loves to use.

Full reference: Big Idea 2 Study Guide

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Big Idea 3 is the largest and most technically demanding. It covers all the programming concepts tested on the exam using College Board pseudocode. No specific programming language is required, but you must be comfortable tracing code written in the AP reference format.

Full reference: Big Idea 3 Study Guide

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Big Idea 4 covers how the Internet works, how data moves between computers, and how systems are designed to handle failures. These questions tend to be conceptual rather than computational.

Full reference: Big Idea 4 Study Guide

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Big Idea 5 is the second largest content area. It covers computing’s effects on society, ethics, and individuals. These questions require no coding knowledge but do require understanding real-world implications of technology decisions.

Full reference: Big Idea 5 Study Guide

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The Create Performance Task (30% of Your Score)

The Create Performance Task is a programming project you complete before exam day. It is submitted through the AP Digital Portfolio approximately 3 weeks before the exam. It is scored by College Board readers and counts for 30% of your AP score — as much as 21 MCQ questions combined.

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The AP CSP Pseudocode Reference — Every Instruction Explained

The AP exam provides a pseudocode reference sheet during the test. Unlike AP CSA, there is no specific programming language — all code on the exam uses this pseudocode. Here is every instruction type explained.

Instruction	What It Does	Key Detail
a ← expression	Assigns the value of expression to variable a	This is assignment, not equality checking
DISPLAY(expression)	Shows the value of expression followed by a space	Similar to print() or System.out.println()
INPUT()	Gets a value from the user and returns it	Usually assigned: x ← INPUT()
a + b, a - b, a * b, a / b	Standard arithmetic operators	Division always returns a decimal (not integer division)
a MOD b	Returns the remainder when a is divided by b	MOD 2 = 0 means even; MOD 2 = 1 means odd
RANDOM(a, b)	Returns a random integer from a to b, inclusive	Both endpoints can be returned
a = b, a ≠ b, a > b, a < b	Relational operators, return true or false	= checks equality here (not assignment like in Java)
NOT condition	True if condition is false, false if condition is true	Flips a boolean value
condition1 AND condition2	True only if both conditions are true	Short-circuits: if first is false, second not evaluated
condition1 OR condition2	True if at least one condition is true	Short-circuits: if first is true, second not evaluated
IF (condition) { }	Executes block only if condition is true	No action if condition is false and no ELSE
IF (condition) { } ELSE { }	First block if true, second block if false	Exactly one block always executes
REPEAT n TIMES { }	Executes block exactly n times	n must be a positive integer
REPEAT UNTIL (condition) { }	Repeats until condition becomes true	Runs at least once; condition checked after each iteration
FOR EACH item IN list { }	Iterates over each element in list	item takes each value in order; 1-based indexing
list[i]	Returns the element at index i (1-based)	First element is list[1], not list[0]
INSERT(list, i, value)	Inserts value at index i, shifts elements right	All elements from i onward move up one position
APPEND(list, value)	Adds value to the end of the list	Size increases by 1
REMOVE(list, i)	Removes element at index i, shifts left	All elements after i move down one position
LENGTH(list)	Returns the number of elements in the list	Works on lists and strings
PROCEDURE name(params) { }	Defines a reusable block of code with parameters	Call with name(arguments) to execute
RETURN(expression)	Returns a value from a procedure	Execution returns to the caller

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Frequently Asked Questions

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Official source: This page is based on the College Board AP CSP Course and Exam Description (PDF). Always verify against the official document for the most current information.

Where to Go From Here

• Daily Practice (QOTD) — Free daily CSP questions organized by Big Idea
• AP CSP Test Builder — Build a custom practice exam from 500+ questions
• Big Idea 1 Study Guide — Creative Development deep dive
• Big Idea 2 Study Guide — Data, binary, compression, privacy
• Big Idea 3 Study Guide — All AAP topics with pseudocode examples
• Big Idea 4 Study Guide — Internet, fault tolerance, parallel computing
• Big Idea 5 Study Guide — Ethics, privacy, bias, security