AP Computer Science Principles (AP CSP) Review

Practice flashcards covering the major concepts of AP Computer Science Principles including Creative Development, Data, Programming, Networks, and Impact of Computing.

What is a computing innovation?

A computing innovation uses a computer program to take in data, transform data, and output data.

What are the benefits of collaboration in the software development process?

Benefits include the ability to exchange ideas, discuss different solutions, incorporate multiple perspectives for improvements, address misunderstandings, increase student responsibility, and eliminate bias.

What is pair programming?

Pair programming is when two programmers develop software side-by-side at one computer on the same algorithm.

Define a user interface.

The inputs and outputs that allow a user to interact with a piece of software.

What is the difference between an input and an output?

Input is data sent to a computer for processing into a device, while output is data sent from a program to a device.

What is a program event?

An action or occurrence that takes place within a computer program, such as a button click, mouse movement, or keyboard input, used to trigger specific behaviors.

Contrast event-driven programs and sequential programs.

Event-driven programs respond to events triggered by user actions or system events, whereas sequential programs happen in a specific order.

What is an Application Program Interface (API)?

A library or collection of functions that includes documentation on how each function works, a complete list of parameters, and what is returned.

What is the difference between iterative and incremental development?

In iterative development, programmers develop working prototypes and revisit stages; in incremental development, they break the program into smaller pieces and ensure each works before adding it to the whole.

What is the most common form of program documentation?

Comments, which are written directly into the program (e.g., //This on event allows…).

What is a syntax error?

An error that occurs when spelling or punctuation rules of the programming language are not followed, such as forgetting a semicolon or misusing case-sensitive variables.

Define a logic error.

A mistake in a program's base logic that causes unexpected behavior, such as a program printing 'You got a B' for a grade of 95 because the code checked if the value was greater than 80 before checking higher thresholds.

When does a run-time error occur?

An error that occurs while the program is running, such as trying to perform an undefined operation like $5/0$, which causes the program to crash.

What is an overflow error?

An error that occurs when a computer tries to handle a number that is outside of its defined range of values.

Define a bit and a byte.

A bit is the smallest unit of information (0 or 1); 8 bits form a byte, which has $256$ unique combinations.

What is the difference between analog and digital data?

Analog data is measured continuously and changes smoothly; digital data is a simplified representation formatted in a finite set of possible values, often approximating analog data through abstraction.

How is analog data represented digitally?

Through a sampling technique where the values of the analog signal are measured and recorded at regular discrete intervals known as samples.

What is the formula for the largest value that can be represented with $n$ bits?

$2^n - 1$ (For example, with 8 bits, the largest value is $2^8 - 1 = 255$).

What is the formula for the total number of numerical values that can be represented with $n$ bits?

$2^n$ (For example, 8 bits can represent $256$ total values, from 0 to 255).

Define Lossless Data Compression.

A compression method that reduces file size without losing any original data, allowing the original message to be reconstructed exactly (e.g., Run Length Encoding).

Define Lossy Data Compression.

A compression method that sacrifices some data (like pixels or sound waves) to achieve greater compression; it can only reconstruct an approximation of the original message and is used for images and sound.

What is metadata?

Data about data (e.g., descriptions of a data set). Changes or deletions made to metadata do not affect the primary data itself.

What is the purpose of cleaning data?

Cleaning data creates a uniform data set by addressing issues like incomplete data, invalid data, or the need to combine multiple sources.

What is data mining?

The process of examining very large data sets to find useful information such as patterns.

Explain the difference between a global and a local variable.

Global variables can be used anywhere in the program and are usually defined outside events/functions; local variables are created and only used within the specific part of the code (like an onEvent) where they were created.

What are the rules for Boolean operators (NOT, AND, OR)?

NOT (!) reverses the value (NOT true is false); AND (&&) is true ONLY if both conditions are met; OR (||) is true if at least one condition is met.

What index number do lists start at in AP CSP pseudocode?

Index numbers start at $1$ (not 0).

What is the function of the MOD (modulo) operator?

$a ext{ MOD } b$ gives the remainder after $a$ is divided by $b$ (e.g., $27 ext{ MOD } 4 = 3$).

Compare linear search and binary search algorithms.

Linear search checks each element in order; Binary search starts in the middle of a sorted data set and eliminates half of the data each step; Binary search is more efficient but requires the data to be in order.

What are the three building blocks of algorithms?

Sequencing (steps in order), Selection (making decisions with If/Else), and Iteration (repeating steps with loops).

What is an undecidable problem?

A decision problem for which no algorithm can be written that provides a correct 'yes' or 'no' answer for all cases, such as the Halting Problem created by Alan Turing.

What is a heuristic solution?

An approximate solution used when a problem cannot be solved in a reasonable amount of time.

What is the difference between the Internet and the World Wide Web?

The Internet is a network of interconnected networks using open protocols like TCP/IP; the World Wide Web is a system of web pages and files governed by the HTTP protocol.

Define TCP, IP, and UDP.

IP (Internet Protocol) addresses and moves packets; TCP (Transmission Control Protocol) ensures reliable, ordered, and error-checked delivery; UDP (User Datagram Protocol) offers faster delivery by eliminating error checking, but does not guarantee order or arrival.

Contrast IPv4 and IPv6.

IPv4 uses 32-bit addresses (approx. $2^{32}$ values) split into 4 numbers (0-255); IPv6 uses 128-bit hexadecimal addresses (approx. $2^{128}$ values) to handle more devices.

What is fault tolerance?

The capacity for a system to function properly even if one or more components fail, typically achieved through redundancy (extra components).

What is the 'speedup' of a parallel solution?

The sequential execution time divided by the parallel execution time.

Define the Digital Divide.

The gap between those who have access to technology and the internet and those who do not, influenced by demographics, socioeconomics, and geography.

What is crowdsourcing and citizen science?

Crowdsourcing is getting input from a large group of people via the internet; Citizen Science is a form of crowdsourcing where the general population contributes data to scientific research.

What are the PANE factors of Fair Use?

Purpose (originality), Amount (portion of work used), Nature (factual vs. creative), and Effect (financial impact on the original creator).

What is Multi-factor Authentication (MFA)?

A security method requiring multiple identification categories: Knowledge (password/PIN), Possession (phone/badge), or Inheritance (biometrics like fingerprints).

Explain Public Key (Asymmetric) Encryption.

A system that uses a public key to encrypt a message and a different private key to decrypt it; it relies on digital certificates issued by Certificate Authorities (CAs) to verify trust.