Guide to AP Computer Science Principles Reference Sheet 2024

The AP Computer Science Principles (AP CSP) exam assesses knowledge of fundamental computing concepts, programming basics, and the societal effects of technology. Central to success is the official AP Computer Science Principles reference sheet, which specifies the pseudocode format used on the exam. This guide explains the contents of the reference sheet, how it supports preparation, and how to use it effectively. Knowing its layout helps students understand code questions and do well on both the multiple-choice section and the Create task.

Exam Structure and the Role of the Reference Sheet

The AP CSP exam has two components: the Create performance task and the end-of-year digital exam. The Create task, completed during class time, makes up 30% of the total score. It requires students to build a program and submit a video, written responses, and a personal project reference that includes code excerpts. The other 70% comes from the year-end exam, delivered through the College Board’s Bluebook platform. This part takes three hours and includes 70 multiple-choice questions and two written responses.

The multiple-choice section contains single-select and multiple-select questions on computational thinking, data, algorithms, programming, networks, and the global impact of computing. Code-related questions use a standard pseudocode format defined in the reference sheet. Students are not expected to know Python, Java, or any specific programming language. They must read and trace pseudocode using the rules in the official document.

This standard format ensures fairness across classrooms that may teach different languages. The reference sheet is available during the exam, so students need to use it quickly and correctly. It can be accessed through official College Board resources and should be used throughout the course for practice.

What’s Included in the Reference Sheet

The reference sheet outlines the pseudocode syntax used on the exam. It covers variables, math operations, lists, conditionals, loops, and procedures. The format does not favor any real programming language and focuses on general computing ideas.

Key features include:

• Variable assignment: Uses a left-pointing arrow (←). For example, x ← 5 assigns the value 5 to variable x.
• Mathematical operators: Includes +, −, *, /, and MOD for modulus.
• Lists: Supports creation, indexing, insertion, and removal. Lists are 1-indexed, so the first element is at position 1.
• Conditionals: Uses IF, ELSE IF, and ELSE blocks with Boolean logic (AND, OR, NOT).
• Loops: Includes REPEAT n TIMES and REPEAT UNTIL(condition).
• Procedures: Allows defining custom functions with or without parameters.
• Built-in functions: Includes RANDOM(a, b) to generate a random integer between a and b, and LENGTH(list) to return the number of elements in a list.

An example of pseudocode from the reference sheet:

i ← 1
REPEAT 5 TIMES
    DISPLAY(i)
    i ← i + 1

This loop displays the numbers 1 through 5. The DISPLAY command outputs values, and the variable i increases by 1 each time. Students must follow each step to predict output or find errors.

The reference sheet does not include every feature of a full programming language. It leaves out object-oriented programming, file handling, and error handling. Input uses INPUT(), and output uses DISPLAY(), keeping the focus on logic rather than syntax.

How Pseudocode Differs from Real Programming Languages

The exam’s pseudocode is simpler and more consistent than real programming languages, with key differences. One is indexing: lists use 1-based indexing. In Python or Java, the first list element is at index 0; in AP CSP pseudocode, it is at index 1. This changes how expressions like list[1] are interpreted and must be practiced to prevent mistakes.

Another difference is syntax. There are no semicolons, braces, or strict indentation rules. Loops and conditionals use clear keywords like REPEAT and IF, making structure easy to follow without language-specific formatting. Procedures are defined without return types or access modifiers.

Students should not try to convert pseudocode line by line into Python or another language. They should read it using the reference sheet as a guide. Practice with past exam questions builds skill in tracing and understanding the format as it appears.

Preparing for the Create Performance Task

The Create task lets students design and build an original program. Over about 12 hours of class time, they create a project that shows computational thinking and programming ability. Submissions include:

• A one-minute video showing the program in action.
• Two written responses (300 words each) describing the program’s purpose, how it was made, and how it uses algorithms and abstraction.
• A personal project reference: a one-page PDF with code excerpts that show an algorithm and a list.

The personal project reference does not need the full program. It should highlight original code written by the student, such as a loop, procedure, or data-processing step. The College Board reviews this to evaluate how students apply programming concepts.

The video must show the program working without spoken commentary. Many students use screen recordings with text captions to explain features. The written responses must answer the prompts directly and stay within the word limit.

Students should follow the scoring guidelines closely and save drafts of their work. The AP Classroom platform offers submission instructions and sample projects to support planning.

Study Strategies and Practice Resources

Good preparation includes regular practice with the reference sheet. Students should trace pseudocode by hand, noting how variables change at each step. This improves accuracy when predicting output or finding logic problems.

Official College Board materials are the most accurate resources. The course and exam description (CED), AP Classroom progress checks, and released exam questions match the actual test format. Teachers can assign these for class review or homework.

Students can also write pseudocode for simple programs, such as a number guessing game or a list sorter. Working in pairs to trace each other’s code strengthens understanding of syntax and logic.

Other useful resources include review guides and instructional videos from trusted educational platforms like Khan Academy and Code.org Wikipedia. Reviewing the seven Big Ideas—Creative Development, Data, Algorithms, Programming, Computer Systems and Networks, Cybersecurity, and Global Impact—supports broad conceptual understanding.

Key Takeaways

• The AP Computer Science Principles reference sheet defines the pseudocode used on the exam and is essential for interpreting code-based questions.
• The exam includes 70 multiple-choice questions and a Create performance task, with code presented in a standardized format.
• Pseudocode uses 1-based indexing and simplified syntax, so students must practice tracing it independently of their course language.
• For the Create task, students submit a video, written responses, and a personal project reference showing key code elements.
• Use official College Board materials and consistent practice to build confidence and accuracy.