AP comp/sci

Binary

A way of representing information using only two options.

Bit

A contraction of "Binary Digit"; the single unit of information in a computer, typically represented as a 0 or 1

Byte

8 bits

Overflow Error

Error from attempting to represent a number that is too large.

Round-off Error

Error from attempting to represent a number that is too precise. The value is rounded.

Analog Data

Data with values that change continuously, or smoothly, over time. Some examples of analog data include music, colors of a painting, or position of a sprinter during a race.

Digital Data

Data that changes discretely through a finite set of possible values

Sampling

A process for creating a digital representation of analog data by measuring the analog data at regular intervals called samples.

Lossless Compression

A process for reducing the number of bits needed to represent something without losing any information. This process is reversible.

Lossy Compression

A process for reducing the number of bits needed to represent something in which some information is lost or thrown away. This process is not reversible.

Information

the collection of facts and patterns extracted from data

Metadata

data about data

Cleaning Data

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

Data filtering

choosing a smaller subset of a data set to use for analysis, for example by eliminating / keeping only certain rows in a table

Correlation

a relationship between two pieces of data, typically referring to the amount that one varies in relation to the other.

Data bias

data that does not accurately reflect the full population or phenomenon being studied

Crowdsourcing

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

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.

Intellectual Property

A work or invention that is the result of creativity, such as a piece of writing or a design, to which one has rights and for which one may apply for a patent, copyright, trademark, etc.

Creative Commons

A collection of public copyright licenses that enable the free distribution of an otherwise copyrighted work, used when an author wants to give people the right to share, use, and build upon a work that they have created

Computing Device

a machine that can run a program, including computers, tablets, servers, routers, and smart sensors

Computing System

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

Computing Network

a group of interconnected computing devices capable of sending or receiving data.

Path

the series of connections between computing devices on a network starting with a sender and ending with a receiver.

Bandwidth

the maximum amount of data that can be sent in a fixed amount of time, usually measured in bits per second.

Protocol

An agreed-upon set of rules that specify the behavior of some system

IP Address

The unique number assigned to each device on the Internet.

Internet Protocol (IP)

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

Router

A type of computer that forwards data across a network

Packet

A chunk of data sent over a network. Larger messages are divided into packets that may arrive at the destination in order, out-of-order, or not at all.

Redundancy

the inclusion of extra components so that a system can continue to work even if individual components fail, for example by having more than one path between any two connected devices in a network.

Fault Tolerant

Can continue to function even in the event of individual component failures. This is important because elements of complex systems like a computer network fail at unexpected times, often in groups.

HTTP

HyperText Transfer Protocol - the protocol used for transmitting web pages over the Internet

Internet

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

World Wide Web

a system of linked pages, programs, and files.

Digital Divide

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

User Interface

the inputs and outputs that allow a user to interact with a piece of software. User interfaces can include a variety of forms such as buttons, menus, images, text, and graphics.

Input

data that are sent to a computer for processing by a program. Can come in a variety of forms, such as tactile interaction, audio, visuals, or text.

Output

any data that are sent from a program to a device. Can come in a variety of forms, such as tactile interaction, audio, visuals, or text.

Program Statement

a command or instruction. Sometimes also referred to as a code statement.

Program

a collection of program statements. Programs run (or “execute”) one command at a time.

Sequential Programming

program statements run in order, from top to bottom.

Event Driven Programming

some program statements run when triggered by an event, like a mouse click or a key press

Event

associated with an action and supplies input data to a program. Can be generated when a key is pressed, a mouse is clicked, a program is started, or by any other defined action that affects the flow of execution.

Documentation

a written description of how a command or piece of code works or was developed.

Comment

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

Pair Programming

a collaborative programming style in which two programmers switch between the roles of writing code and tracking or planning high level progress

Debugging

Finding and fixing problems in an algorithm or program.

Development process

the steps or phases used to create a piece of software. Typical phases include investigating, designing, prototyping, and testing

Expression

a combination of operators and values that evaluates to a single value

Assignment Operator

allows a program to change the value represented by a variable

Variable

a named reference to a value that can be used repeatedly throughout a program.

String

an ordered sequence of characters.

Boolean Value

a data type that is either true or false.

Comparison Operators

Logical operator

NOT, AND, and OR, which evaluate to a Boolean value.

Conditional Statement

affect the sequential flow of control by executing different statements based on the value of a Boolean expression.

Function

a named group of programming instructions. Also referred to as a “procedure”.

Function Call

a command that executes the code within a function