APCSP Vocab

Computing Innovation

includes a program as an integral part of its function. They can be physical (e.g., self-driving car), non-physical computing software (e.g., picture editing software), or non-physical computing concepts (e.g., e-commerce). The purpose of computing innovations is to solve problems or pursue interests through creative expression

Program

a collection of program statements that performs a specific task when run by a computer. A program is often referred to as software

Code segment

a collection or program statements that is part of a program

Behavior (of a program)

how a program functions during execution and is often described by how a user interacts with it

Program inputs

data sent to a computer for processing by a program. Input can come in a variety of forms, such as tactile, audio, visual, or text

Event

associated with an action and supplies input data to a program (key pressed, mouse clicked, program started, or any other defined action occurs that affects the flow of execution)

Program outputs

any data sent from a program to a device. Program outputs can come in a variety of forms, such as tactile, audio, visual, or text

Program documentation

a written description of the function of a code segment, event, procedure, or program and how it was developed

Comments

a form of program documentation written into the program to be read by people and do not affect how a program runs

Logic error

a mistake in the algorithm or program that causes it to behave incorrectly or unexpectedly

Syntax error

a mistake in the program where the rules of the programming language are not followed

Run-time error

a mistake in the program that occurs during the execution of a program. Programming languages define their own run-time errors

Overflow error

an error that occurs when a computer attempts to handle a number that is outside of the defined range of values

Testing

uses defined inputs to ensure that an algorithm or program is producing the expected outcomes

Bit

shorthand for binary digit and is either 0 or 1. Bits are grouped to represent abstractions, such as numbers, characters, colors, etc. The same sequence of bits may represent different types of data in different contexts

Byte

8 bits

Abstraction

the process of reducing complexity by focusing on the main idea. By hiding details irrelevant to the question at hand and bringing together related and useful details, abstraction reduces complexity and allows one to focus on the idea

Sampling technique

measuring values of the analog signal at regular intervals called samples.

Binary (base 2)

uses only combinations of the digits zero and one

Decimal (base 10)

uses only combinations of the digits 0 - 9

Data compression

can reduce the size (number of bits) of transmitted or stored data

Lossless compression

these algorithms can usually reduce the number of bits stored or transmitted while guaranteeing complete reconstruction of the original data

Lossy compression

these algorithms can significantly reduce the number of bits stored or transmitted but only allow reconstruction of an approximation of the original data. Lossy data compression algorithms can usually reduce the number of bits stored or transmitted more than lossless compression algorithms

Information

the collection of facts and patterns extracted from data

Metadata

data about data. For example, the piece of data may be an image, while the metadata may include the date of creation or the file size of the image

Cleaning data

a process that makes the data uniform without changing their meaning (e.g., replacing all equivalent abbreviations, spellings, and capitalizations with the same word)

Parallel systems

may be required to process large data sets

Variable

an abstraction inside a program that can hold a value. Each variable has associated data storage that represents one value at a time, but that value can be a list or other collection that in turn contains multiple values

Types

some programming languages provide types to represent data, which are referenced using variables. These types include numbers, Booleans, lists, and strings

List

an ordered sequence of elements

Element

an individual value in a list that is assigned a unique index

Index

a common method for referencing the elements in a list or or string using natural numbers

String

an ordered sequence of characters

Algorithm

a finite set of instructions that accomplish a specific task

Sequencing

the application of each step of an algorithm in the order in which the code statements are given

Code statement

a part of program code that expresses an action to be carried out

Expression

can consist of a value, a variable, an operator, or a procedure call that returns a value. They are evaluated to produce a single value

MOD (modulo operator)

evaluates to the remainder after division

String concatenation

joins together two or more strings end-to-end to make a new string

Substring

part of an existing string

Boolean value

a value that is either true or false

Logical operators

NOT, AND, and OR, which evaluate to a Boolean value (true/false)

Selection

determines which parts of an algorithm are executed based on a condition being true or false (if-statements)

Iteration

a repeating portion of an algorithm. Iteration repeats a specified number of times or until a given condition is met (for loops and while loops)

Traversing a list

accessing either a portion of elements in a list or all elements in a list (for loop processing a list)

Linear search algorithms

check each element of a list, in order, until the desired value or found or all elements in the list have been checked

Binary search algorithm

starts at the middle of a sorted data set of numbers and eliminates half of the data; this process repeats until the desired value is found or all elements have been eliminated

Procedure

a named group of programming instructions that may have parameters and return values (called function in JavaScript/App Lab)

Parameter

an input variable of a procedure (function). Allows functions (procedures) to be generalized, enabling the functions (procedures) to be reused with a range of input values or arguments

Argument

specifies the value of the parameter when a procedure (function) is called

Procedural abstraction

provides a name for a process and allows a procedure to be used only knowing what it does, not how it does it

Modularity

the subdivision of a computer program into separate subprograms

(Software) Library

contains functions (procedures) that may be used in creating new programs

Application program interface (API)

specifications for how the functions (procedures) in a library behave and can be used

Simulation

a representation that uses varying sets of values to reflect the changing state of a phenomenon. They often mimic real-world events with the purpose of drawing inferences, allowing investigation of a phenomenon without the constraints of the real world

Problem

a general description of a task that can (of cannot) be solved algorithmically. An instance of a problem also includes specific input

Decision problem

a problem with a yes/no answer (e.g., is there a path from A to B?)

Optimization problem

a problem with the goal of finding the "best" solution among many (e.g., what is the shortest path from A to B?)

Efficiency

an estimation of the amount of computational resources used by an algorithm. Efficiency is typically expressed as a function of the size of the input (n)

Reasonable amount of time

algorithms with a polynomial efficiency or lower (constant, linear, square, cube, etc. - n, 10*n, n2, n3)

Unreasonable amount of time

algorithms with exponential or factorial efficiencies (2n or n!)

Heuristic

an approach to a problem that produces a solution that is not guaranteed to be optimal but may be used when techniques that are guaranteed to always find an optimal solution are impractical

Decidable problem

a decision problem for which an algorithm can be written to produce a correct output for all inputs (e.g., "Is the number even?")

Undecidable problem

a decision problem for which no algorithm can be constructed that is always capable of providing a correct yes-or-no answer

Computing device

a physical artifact that can run a program. Some examples include computers, tablets, servers, routers, and smart sensors

Computing system

a group of computing devices and programs working together for a common purpose

Computer network

a group of interconnected computing devices capable of sending or receiving data. A computer network is a type of computing system

Path

a sequence of directly connected computing devices that begins at the sender and ends at the receiver

Routing

the process of finding a path from sender to receiver

Bandwidth

the maximum amount of data that can be sent in a fixed amount of time over a computer network. Bandwidth is usually measured in bits per second

The Internet

a computer network consisting of interconnected networks that use standardized, open (nonproprietary) communication protocols

Protocol

an agreed-upon set of rules that specify the behavior of a system

Scalability

the capacity for a system to change in size and scale to meet new demands

Data stream

information passed through the Internet

Packet

an encapsulated chunk of data passed through a network. Packets may arrive at the destination in order, out of order, or not at all

IP (Internet Protocol)

a protocol for sending data across the Internet that assigns unique numbers (IP addresses) to each connected device

TCP (Transmission Control Protocol)

a protocol for sending packets that does error-checking to ensure all packets are received and properly ordered

UDP (User Datagram Protocol)

a protocol for sending packets quickly with minimal error-checking and no resending of dropped packets

HTTP

a protocol used by the World Wide Web, which uses the Internet

DNS (Domain Name System)

the system responsible for translating domain names like example.com into IP addresses

Redundancy

the inclusion of extra components that can be used to mitigate failure of a system if other components fail

Fault tolerance

when a system can support failures and still continue to function. This is important because elements of complex systems fail at unexpected times, often in groups, and fault tolerance allows users to continue to use the network

Sequential computing

a computational model in which operations are performed in order one at a time. A sequential solution takes as long as the sum of all of its steps

Parallel computing

a computational model where the program is broken into multiple smaller sequential computing operations, some of which are performed simultaneously. A parallel computing solution takes as long as its sequential tasks plus the longest of its parallel tasks

Speedup (of a parallel solution)

measured in the time is took to complete the task sequentially divided by the time it took to complete the task when done in parallel

Distributed computing

a computational model in which multiple devices are used to run a program. This allows problems to be solved that could not be solved on a single computer and allos much larger problems to be solved quicker than they could using a single computer

Digital Divide

differing access to computing devices and the Internet, based on socioeconomic, geographic, or demographic characteristics

Citizen science

scientific research conducted in whole or part by distributed individuals, many of whom may not be scientists, who contribute relevant data to research using their own computing devices

Crowdsourcing

the practice of obtaining input of information from a large number of people via the Internet

Intellectual property

material created on a computer is the intellectual property of the creator or an organization

Creative Commons

a public copyright license that enables the free distribution of an otherwise copyrighted work. This is used when the content creator wants to give others the right to share, use, and build upon the work they have created

Open source

programs that are made freely available and may be redistributed and modified

Open access

online research output free of any and all restrictions on access and free of many restrictions on use, such as copyright or license restrictions

Personally identifiable information (PII)

information about an individual that identifies, links, relates, or describes them. Examples: social security number, age, race, phone number(s), medical information, financial information, biometric data

Authentication measures

protect devices and information from unauthorized access. Examples: strong passwords and multifactor authentication

Multifactor authentication

a method of computer access control in which a user is only granted access after successfully presenting several separate pieces of evidence to an authentication mechanism, typically in at least two of the following categories: knowledge (something they know), possession (something they have), and inherence (something they are)

Encryption

the process of encoding data to prevent unauthorized access

Decryption

the process of decoding encrypted data

Symmetric key encryption

uses one key for both encryption and decryption

Public key (asymmetric) encryption

pairs a public key for encryption and a private key for decryption. The sender does not need the receiver's private key to encrypt a message, but the receiver's private key is required to decrypt the message