APCSP Computational Thinking Practices 5

Question 1

A student is writing a program to sort a list of names. She first writes a version that works correctly, then revises it to be faster. What two computational thinking practices does this sequence demonstrate?

Accepted Answer

Correctness first, then optimization

Answer

Getting a correct solution before optimizing it is a best practice — it separates the goal of correctness from the goal of efficiency.

Question 2

Which of the following is the BEST reason to use a model or simulation instead of a real-world experiment?

Accepted Answer

Simulations are cheaper, faster, or safer when real experiments are impractical

Answer

Simulations are used when real experiments are too expensive, dangerous, slow, or logistically impossible (e.g., simulating a nuclear reactor or climate change).

Question 3

A student writes a program that checks whether a number is prime. She tests it on 2, 3, 7, and 11 and it works. Then she tests it on 1 and it returns 'prime' — which is incorrect. What type of input did she fail to account for?

Accepted Answer

A boundary / edge case

Answer

The number 1 is a boundary case (edge case) that behaves differently from typical primes — failing to test it revealed a bug in the logic.

Question 4

Which of the following statements about data abstraction is MOST accurate?

Accepted Answer

Data abstraction allows programmers to use data structures without knowing their underlying implementation

Answer

Data abstraction lets programmers use lists, dictionaries, and other structures based on their interface and behavior, without needing to know how they are implemented internally.

Question 5

A student evaluates two algorithms that both solve the same problem. Algorithm A always takes 1 second regardless of input size; Algorithm B takes longer as input size grows. Which algorithm is MORE scalable?

Accepted Answer

Algorithm A, because its runtime does not grow with input size

Answer

Algorithm A has constant time complexity, meaning it scales perfectly — its performance does not degrade as input size increases.

(APCSP) AP Computer Science Principles Practice Test

(APCSP) AP Computer Science Principles Practice Test

APCSP Computational Thinking Practices 5