Unit 1: Creative Development
AP Computer Science Principles: 52 practice questions with detailed explanations.
Unit Study Guide
Executive Summary
Computing is collaborative problem solving. This unit covers how computing innovations are defined, how teams develop programs, and how errors are found and fixed.
Computing innovations
A computing innovation includes a program as an integral part of its function — apps, self-driving cars, social media. It can be physical or nonphysical. The program's PURPOSE is why it exists; its FUNCTIONALITY is what it does. Input comes from users, sensors, or files; output can be text, images, or sound.
Development process
Design is iterative: investigate, design, prototype, test, refine — repeating cycles. Incremental development builds small pieces; iterative development revisits and improves versions. Teams use pair programming, clear communication, and divided work; diverse perspectives improve designs.
Errors
Syntax errors break the language's rules and prevent running. Logic errors run but produce wrong results. Runtime errors crash during execution. Testing finds errors with varied and edge-case inputs; debugging fixes them. Boundary values and unusual inputs reveal hidden bugs.
Exam traps
Know the exact College Board definition of computing innovation (a program must be integral). Distinguish purpose from functionality. Testing and debugging are different activities.