Differences Between AP Computer Science A and AP Computer Science Principles

Since the introduction of AP Computer Science Principles, the interest between AP Computer Science A (CSA) and AP Computer Science Principles (CSP) has fluctuated throughout the years. Test-takers frequently asked us what test will be beneficial to their future major in college. Wait no more, read the article below to learn more about the similarities and differences between the two subjects.
Differences between AP Computer Science A and AP Computer Science Principles

In 2020, more than 100,000 students took the AP CSP Exam — almost triple the number of exam takers in the course’s first year. In the meantime, it took CSA 10 years to triple the number of test-takers since 2010.  With the rising popularity of CSP, many test-takers are geared towards the latter test. However, before making the decision to take either AP tests, we would like to address some questions that will better inform you before finalizing your decision:  

  1. What are the course and exam contents of each subject?  
  2. What is the score distribution of the two exams? 
  3. Who should take CSA and/or CSP? 
Course and Exam Content
1. What are the course and exam contents of AP Computer Science A? 

Course objective: AP Computer Science A is equivalent to a first-semester, college-level course in computer science. AP CSA focuses on computing skills related to programming in Java, and students without prior computer science experience can do well in this course. It is recommended that students should complete first-year high school algebra before taking this course. Besides learning the language, students are required to take 20 hours of hands-on, structured lab time to practice their problem-solving skills through Java programming.  

Course content: The main course content for CSA covers a subset of the Java programming language. The course helps students to analyze, write, and test codes through introducing Primitive Types, Objects, Boolean Expressions and if Statements, Iteration, Classes, Array, 2D Array, and ArrayList, Inheritance, Recursion 

Exam content: Basic programming (55-75%), data structure (24-40%), logic (5-10%), algorithm/requirement solution (25-45%), object-oriented programming (15-25%), iteration (5-15%), software engineering (2-10%). 

Exam time: 3 hours 

Exam distribution: 

  • Section I: Multiple choice questions: 40 questions, 1 hour and 30 minutes in total, accounted for 50% of the test score
  • Section II (similar across paper and digital):  4 Free-Response questions, accounted for 50% of the test score. 4 questions test your programming ability in understanding control structures, classes, Array/ArrayList, and 2D Array.  
2. What are the course and exam contents of AP Computer Science Principles?

Course objective: AP Computer Science Principles is equivalent to a first-semester, college-level breadth course in computer science. The general course objectives of CSP are similar to CSA, but it focuses on more problem solving through the development of algorithms and programs, and understanding the impacts of computer science. Please also note that the course doesn’t have a designated programming language. Therefore, please make sure to check the course syllabus for the intended language of education.   

Course content: AP Computer Science Principles builds upon CSA and provides broader aspects of computing. Therefore, the course content focuses on introducing big ideas of computer science applications in multiple contexts 

Big idea 1: Creative Development – understand the importance of collaboration and program development 

Big idea 2: Data – practice data compressions and extracting information from data  

Big idea 3: Algorithm and Programming – use algorithm and abstraction to solve problems 

Big idea 4: Computer System and Networks – Internet and Parallel and distributed computing  

Big idea 5: Impact of Computing – the social, economic, cultural, ethical, and legal impact of computing and programmers. 

Exam content: Creative development (10-13%), data information (17-22%), algorithm and programming (30-35%), computer system network (11-15%), impact of computing (21-26%). 

CSP Exam includes the Create performance task, which is completed during the course, and an end-of-course multiple-choice exam. 

  • Create Performance Tasks (30% of the score): develop a computer program that solves a problem, enables innovation, or helps students express personal interests. The submission includes: a video of the program running, written responses about the program and the development process, and program codes.  
  • End of Course Exam  

Exam time: 2 hours 

Exam distribution: (70% of the score) 70 multiple choice questions, 4 answer options 

The end-of-course multiple-choice exam is a paper-and-pencil written exam. It contains three types of multiple-choice questions: 

  • Single-select multiple-choice: You select 1 answer from 4 options
  • Single-select with a reading passage about a computing innovation: You select 1 answer from 4 options.
  • Multiple-select multiple-choice: You select 2 answers from 4 options 
Score Distribution

The score distribution of each AP CS exam is also a good reference for students to prepare accordingly. The following is the score distribution of each in 2020 (the number is rounded up to the nearest whole number: 


5 points 

4 points 

3 points 

2 minutes 

1 point 

AP Computer Science A 






AP Computer Science Principles 






Who should take CSA and/or CSP?
1. CSA is deeper and less broad, while CSP is broader and less deep.

CSA is an introductory CS course, while CSP is a conceptual course. Specifically, CSP’s main purpose is to increase the number of students exposed to CS, while CSA’s main purpose is to teach Java programming. CSA test is based on your ability to understand and write Java, while CSP’s test is based on your understanding of programming and computer science applications. However, CSP also requires you to develop a computer program that takes up around 12 hours. 

Comp sci
Source: Internet

CSA score gives you credit transfer to more schools than CSP. A four or higher in CSP earns you college credits or advanced placement to 281 schools across the country, while for CSA, it’s more than 551 schools. Therefore, fewer schools give college credit for scores on the AP CS Principles exam than for AP CS A. 

2. Who should take AP Computer Science Principles?

Students who limited-to-no coding experience but are interested in computer science can confidently take this course. If you are in the explotorary stage where you explore different major options, this introductory course will definitely ignite your interest in programming and computer science in a broad context.  

According to Ashley, a student who has taken both CSP and CSA, she said: 

“I took the AP Computer Science Principles exam while taking the AP Computer Science A class. The two exams differed majorly as AP Computer Science Principles was less stressful with 2/3 parts of the exam completed in class while AP Computer Science A was a classic AP exam with multiple-choice sections and free-response questions.” 

3. Who should take AP Computer Science A?

AP Computer Science A is more suitable for students who have a strong interest in computer science or have practice some level of coding prior to enrollment. Specifically, if you’re interested in major in STEM (Science, Technology, Engineering and Math), or major in Computer Science in College, this is definitely the course you should take to give you credit transfer. The college will also expect to see a high score on this exam on your transcript as a confirmation of profound interest in this area. 

4. Should I take both courses?

As a natural progression, students who have taken CSP should also take CSA if they confirm their interest in the field. CollegeBoard mentioned that these courses can be taken in any order.  

We recommend that you should start off with CSP then CSA, or taking both CSP and CSA at the same time, because these courses are similar in terms of basic understanding of data structures and algorithms. 

At Aralia, we offer both AP Computer Science and project-based programming course, where students can kick start their interest and dive further into the world of programming through doing projects and participating in national and international competitions. More course information is available below: 


Description: Computer Science through Programming is a 3-course sequence that introduces students to critical thinking and problem solving with the fundamentals of programming, enabling them to decompose complex problems into elementary steps for practical implementation in a modern programming language. The courses incorporate research, theory, and practice to help reinforce the principles taught in each class.

Project time: Rolling enrollment throughout the year, one class every weekend, 1.5 hours per class 

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