# AP Computer Science Principles exam guide > All five AP Computer Science Principles big ideas with published exam weightings, plus the Create performance task. - Canonical page: https://www.arcadesacademy.com/exams/ap-computer-science-principles - Markdown source: https://www.arcadesacademy.com/exams/ap-computer-science-principles/llms.txt - Exam family: AP exams - Governing body: College Board - Official exam information: https://apstudents.collegeboard.org/courses/ap-computer-science-principles - Who takes it: High school students taking a first computing course, including many with no prior programming experience, who want college credit or a broad introduction to the field. - Follows the fall 2023 course and exam description, from 6 May 2024 to 21 May 2027 - Guide structure last checked against official sources: August 30, 2026 ## Overview AP Computer Science Principles is a broad introduction to computing that is intentionally language-agnostic. The Course and Exam Description organizes the content into five big ideas: creative development, data, algorithms and programming, computer systems and networks, and the impact of computing. Each carries a published weighting on the end-of-course multiple-choice exam. The course is assessed in two parts. Students build a program during at least nine hours of class time and submit program code, a video of it running, and a Personalized Project Reference through the AP Digital Portfolio. On exam day they answer multiple-choice questions and two written-response questions about the code in that reference. Algorithms and programming carries the largest exam weighting, but the impact-of-computing big idea is a close second and is often underprepared because it feels less technical. Arcade Academy is an independent study workspace. Use the official Course and Exam Description and the AP Digital Portfolio requirements as authoritative, particularly for performance-task deadlines and rules, and use the pages below to organize review of the tested content. ## Exam format - **Section I:** 70 multiple-choice questions in 2 hours, 70% of the exam score - **Section II:** The Create performance task, worth 30% of the exam score: program code, a video, and a Personalized Project Reference submitted through the AP Digital Portfolio, plus 2 written-response questions answered on exam day - **Written responses:** The 2 written-response questions contain 4 prompts and are answered in 60 minutes on exam day, with the Personalized Project Reference available for reference - **Performance task time:** At least 9 hours of class time are provided to complete the Create performance task - **Delivery:** The end-of-course exam is fully digital and taken in College Board's Bluebook app - **Score scale:** 1 to 5 ## Scoring The end-of-course multiple-choice section contributes 70% of the score and the Create performance task, including the written responses answered on exam day, contributes 30%. Those combine into a composite score that College Board converts to the reported 1 to 5 scale using cut points set for that year's exam. Colleges set their own credit and placement policies, and some award credit for a general computing requirement rather than for a major course. ## Units AP Computer Science Principles is organized into 5 units. Each one below lists its published weighting where the governing body publishes one, the topics it covers, and study tips specific to it. ### 1. Big Idea 1: Creative Development - Position: 1 of 5 - Published weighting: 10–13% - Page: https://www.arcadesacademy.com/exams/ap-computer-science-principles/big-idea-1-creative-development Big Idea 1 covers how programs are designed, built, and debugged, and how collaboration improves the result. It maps most directly onto the Create performance task, since the same vocabulary of purpose, design process, and error correction appears in both. Understanding the difference between logic, syntax, runtime, and overflow errors is a recurring exam target. #### Topics - **Collaboration** — Why diverse collaboration improves program design, and the practices that make it effective. - **Program function and purpose** — Describing what a program does, its inputs and outputs, and the problem it is meant to solve. - **Program design and development** — Investigating requirements, designing, implementing, and iterating, including using program documentation. - **Identifying and correcting errors** — Logic, syntax, runtime, and overflow errors, and the testing strategies that surface each. #### Study tips - Practice describing a program's purpose and function in two or three precise sentences, which is exactly what the written responses ask for. - Learn the four error types with an example of each; distinguishing them is a common multiple-choice item. - Keep notes on your own development process while building the performance task, since the written responses draw on it. ### 2. Big Idea 2: Data - Position: 2 of 5 - Published weighting: 17–22% - Page: https://www.arcadesacademy.com/exams/ap-computer-science-principles/big-idea-2-data Big Idea 2 covers how computers represent information and how information is extracted from it. Binary representation, the difference between lossy and lossless compression, and the process of cleaning and filtering data to find patterns are the core topics. The unit connects to the impact big idea whenever data quality or bias comes up. #### Topics - **Binary numbers** — Representing numbers in binary, converting between binary and decimal, and the limits of fixed-size storage. - **Data compression** — Lossless versus lossy compression, and the trade-off between file size and fidelity. - **Extracting information from data** — Cleaning, filtering, and transforming data, and the difference between correlation and causation in findings. - **Using programs with data** — How programs process large data sets, and the role of metadata in searching and organizing information. #### Study tips - Practice binary to decimal conversion in both directions until it is fast; it appears reliably on the exam. - Keep one concrete example each of lossy and lossless compression and be able to say when each is preferred. - Rehearse explaining what cleaning a data set involves and why it changes the conclusions you can draw. ### 3. Big Idea 3: Algorithms and Programming - Position: 3 of 5 - Published weighting: 30–35% - Page: https://www.arcadesacademy.com/exams/ap-computer-science-principles/big-idea-3-algorithms-and-programming Big Idea 3 carries the largest published weighting in the course. It covers variables, data abstraction, Boolean logic, conditionals, iteration, lists, procedures, libraries, simulation, and algorithmic efficiency. Exam questions use College Board's pseudocode rather than any particular language, so fluency in reading that notation is essential. #### Topics - **Variables, assignment, and data abstraction** — Storing and updating values, and using lists and other structures to manage complexity. - **Boolean expressions and conditionals** — Relational and logical operators, if and else structures, and nested conditionals. - **Iteration** — Repeat loops and loops over lists, including nested iteration and traversal patterns. - **Developing and testing algorithms** — Building algorithms from sequencing, selection, and iteration, and testing them against edge cases. - **Lists, searching, and sorting** — List operations and traversals, plus linear and binary search and what each requires. - **Procedures, libraries, and simulation** — Writing and calling procedures with parameters and return values, using libraries, and modeling with random values. - **Algorithmic efficiency and undecidable problems** — Reasonable versus unreasonable running times, heuristics, and problems no algorithm can solve. #### Study tips - Trace pseudocode by hand with a variable table; the exam rewards careful tracing more than clever reading. - Practice both the block-based and text-based versions of College Board's pseudocode, since either can appear. - Give this big idea the most review time; its published weighting is the largest of the five. ### 4. Big Idea 4: Computer Systems and Networks - Position: 4 of 5 - Published weighting: 11–15% - Page: https://www.arcadesacademy.com/exams/ap-computer-science-principles/big-idea-4-computer-systems-and-networks Big Idea 4 is the smallest by published weighting and covers how computing systems connect and cooperate. The internet's structure, protocols, and fault tolerance are the main topics, along with parallel and distributed computing and the speedup they can provide. The parallel-computing speedup calculation is a reliable exam item. #### Topics - **The internet** — Packets, routing, protocols, IP addressing, and the layered design that lets the network scale. - **Fault tolerance** — Redundancy and multiple paths, and why a network with more connections is more resilient. - **Parallel and distributed computing** — Dividing work across processors or machines, and the sequential portion that limits total speedup. - **Computing system performance** — Calculating speedup from parallelization and recognizing where additional processors stop helping. #### Study tips - Work several parallel-computing speedup calculations; the arithmetic is simple but the setup trips people up. - Explain fault tolerance with a concrete routing example rather than as a definition. - Keep this big idea in the rotation even though it is the lightest; its questions are among the most predictable. ### 5. Big Idea 5: Impact of Computing - Position: 5 of 5 - Published weighting: 21–26% - Page: https://www.arcadesacademy.com/exams/ap-computer-science-principles/big-idea-5-impact-of-computing Big Idea 5 carries the second largest published weighting and is the least technical, which is exactly why it is often underprepared. It covers beneficial and harmful effects of computing innovations, the digital divide, bias built into computing systems, crowdsourcing, legal and ethical concerns, and safe computing practices. Answers here need specific reasoning rather than general opinion. #### Topics - **Beneficial and harmful effects** — Why the same innovation can produce both, and how effects differ across groups of people. - **The digital divide** — Unequal access to computing by geography, income, and other factors, and its consequences. - **Computing bias** — How bias enters through data, design choices, and assumptions, whether intentionally or not. - **Crowdsourcing** — Using distributed contributions to solve problems, and the strengths and limits of the approach. - **Legal and ethical concerns** — Intellectual property, licensing including open source and Creative Commons, and plagiarism. - **Safe computing** — Personally identifiable information, encryption, authentication, phishing, and malware. #### Study tips - Prepare specific examples rather than general statements; the exam rewards a named innovation with a named effect. - Practice arguing both a benefit and a harm for the same innovation, which is a standard question shape. - Do not skip this big idea because it feels easy; it carries the second largest published weighting. ## Study strategies - Start the Create performance task early and keep the Personalized Project Reference accurate, since the exam-day written responses depend directly on the code it contains. - Weight review by the published percentages, giving algorithms and programming and impact of computing the largest shares. - Practice reading College Board's pseudocode in both block and text form, tracing values by hand rather than reading for gist. - Build an example bank for the impact big idea so answers cite a specific innovation, effect, and affected group. - Rehearse the small set of calculations that recur, including binary conversion and parallel-computing speedup. - Confirm performance-task deadlines and submission rules on the official pages well before they arrive, since late submission affects the score. ## Frequently asked questions ### How is the AP Computer Science Principles Exam structured? There are two components. Section I is 70 multiple-choice questions in 2 hours, worth 70% of the score. Section II is the Create performance task, worth 30%: program code, a video, and a Personalized Project Reference submitted through the AP Digital Portfolio, plus 2 written-response questions containing 4 prompts answered in 60 minutes on exam day. ### Which big ideas do students find most challenging? College Board does not rank difficulty. Students commonly report that algorithms and programming takes the most practice because of pseudocode tracing, and that impact of computing loses more points than expected because answers are too general. Practice results should decide where your time goes. ### How is the exam scored? The multiple-choice section contributes 70% and the performance task with its written responses contributes 30% of a composite score, which is converted to the reported 1 to 5 scale using cut points set each year. Colleges set their own credit policies and some apply this course to a general requirement rather than a computing major. ### Do I need programming experience before taking the course? No. The course is designed as a first computing course and is language-agnostic, with exam questions written in College Board's own pseudocode. Students choose a programming language for the performance task with their teacher. ### When do students usually start the performance task? Schools schedule at least nine hours of class time for it, and a common approach is to begin well before the submission deadline so there is room to test, revise, and prepare the Personalized Project Reference carefully. Confirm current deadlines on the official pages. ### Is Arcade Academy affiliated with College Board? No. AP® is a registered trademark of College Board, which was not involved in the production of, and does not endorse, this site. Arcade Academy is an independent educational resource. ## Related exam guides - [AP Computer Science A](https://www.arcadesacademy.com/exams/ap-computer-science-a): Java programming across the four units of the revised AP Computer Science A framework, with published exam weightings. - [AP Statistics](https://www.arcadesacademy.com/exams/ap-statistics): The revised five-unit AP Statistics framework, from exploring data and collecting it through inference and regression. ## Independence and trademark notice AP® is a registered trademark of College Board, which was not involved in the production of, and does not endorse, this site. Arcade Academy is an independent educational resource. Confirm current exam format, deadlines, and performance-task rules with College Board directly. AP® is a registered trademark of College Board, which was not involved in the production of, and does not endorse, this site. Arcade Academy is an independent educational resource.