AP CSP Midterm
Information passed through the internet in packets
Data stream
A base 10 number with ten possible different digits
Decimal Number
When the IP of a device is made known to different devices, you can easily share messages with other computers on the internet.
Describe how the Internet Protocol (IP) allows devices to easily connect and communicate on the Internet.
Sampling is a method of converting analog into a digital image. Binary sequences are how we sample these analog images, through patterns of 0s and 1s, and RGB pixels are what shows up on our screen when we sample our analog images. They work together because in order to display a color image, you must use binary sequences, combinations of 0s and 1s, in order to convert the analog you see into what you want it to become. Those RGB pixels become the digital image you desire.
Describe how the process of sampling, RGB pixels, and binary sequences work together to display a digital color image.
Data that changes discreetly through a finite set of possible values
Digital Data
Differing access to computing devices and the Internet, based on Socio economic, geographic, or demographic characteristics
Digital Divide
A written description of how a command or a piece of code works or was developed
Documentation
Information does not travel in one piece, but rather as a datastream of packets.
Which of the following is true regarding the way information is transmitted on the Internet?
Decreasing the size of each sample square, thus increasing the number of samples taken.
Which of the following would result in a better digital approximation of an analog black and white image?
Sampling an analog image more frequently produces a digital image with a better representation.
Which statement about analog and digital images is true?
A system of linked pages, programs, and files
World Wide Web
Made up of 8 bits
1 Byte
User interface
A screen with buttons, images, and text
Output
A song is played
Pulling out specific differences to make one solution work for multiple problems.
Abstraction
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
Analog Data
The correct width and height must be input into the pixelation widget to produce the image. The fact that only 32 bits were used to represent the image indicates relatively large sample squares were used. The digital image may vary from the analog image significantly.
Assume your friend just sent you 32 bits of pixel data (just the 0s and 1s for black and white pixels) that were encoded after sampling an image. Choose the two statements that are true.
The maximum amount of data that can be sent in a fixed amount of time, usually measured in bits per second
Bandwidth
10^0,1,2,3,4,5,6,7,8,9
Base 10 number
2^0,1,2...
Base 2 number
A number system only using 1 and 0
Binary
A base 2 number with two possible different digits
Binary Number
Binary digit in a place value
Bit
The World Wide Web is a collection of pages and files that is shared between computers using HTTP HTTP and the World Wide Web both rely on other layers of protocols for sending information on the Internet
Choose the two statements that best describe the relationship between HTTP and the World Wide Web
Form of program documentation written into the program to be read by people and which do not affect how a program runs
Comment
A machine that can run a program, including computers, tablets, servers, routers, and smart sensors
Computing Device
A group of interconnected computing devices capable of sending or receiving data
Computing Network
A group of computing devices and programs working together for a common purpose
Computing System
Program statements run in order, from top to bottom No user interaction Code runs the same way every time
Sequential Programming
Some program statements run when triggered by an event, like a mouse click or a key press Programs run differently each time depending on user interactions
Event Driven Programming
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
Fault Tolerant
Goes from 2^0 to 2^7
Flippy Doo
Creative Commons applies to copyrighted work while Copyright immediately applies to originally created work.
How is a Creative Commons license different from a regular copyright?
The World Wide Web are files, web pages, and media The Internet is the network we use to access those files
How is the World Wide Web different from the Internet?
A protocol for computers to request and share the pages that make up the World Wide Web on the Internet
Hypertext Transfer Protocol (HTTP)
The unique number assigned to each device on the internet
IP Address
The mailman would sometimes take a different path to deliver each letter to your home Letters would be written on the outside of the envelope for all to read instead of letters put inside envelopes
If the post office delivered mail exactly like the routers deliver messages on the Internet, which of the following statements would be true?
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
Input
a protocol for sending data across the Internet that assigns unique numbers (IP addresses) to each connected device
Internet Protocol (IP)
Digital Image Layer —> Sampling Layer—>Pixel Layer—>Binary Layer
Layers of Abstraction
A process for reducing the number of bits needed to represent something without losing any information. This process is reversible
Lossless 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
Lossy Compression
When a car drives beyond its maximum reading, it doesn't still show the distance driven. Instead, it resets to 0.
Modern car odometers can record up to a million miles driven. What happens to the odometer reading when a car drives beyond its maximum reading?
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
Output
Error from attempting to represent a number that is too large
Overflow Error
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
Packet
Data added to packets to help route them through the network and reassemble the original message
Packet Metadata
A collaborative program in style in which to programmers switch between the roles of writing code and tracking or planning high-level progress
Pair Programming
The series of connections between computing devices on a network starting with a sender and ending with a receiver
Path
Each device or computer on the Internet is assigned a unique IP address. IP is the shared way that all devices and computers label their messages with the sender and receiver's addresses.
Pick the two statements that are true about the Internet Protocol (IP):
A collection of program statements. Programs run or execute one command at a time
Program
A command or instruction. Sometimes also referred to as a code statement
Program Statement
An agreed-upon set of rules that specify the behavior of some system
Protocol
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
Redundancy
Error from attempting to represent a number that is too precise. The value is rounded
Round-off Error
A type of computer that forwards data across a network
Router
A process for creating a digital representation of analog data by measuring the analog data at regular intervals called samples
Sampling
The capacity for the system to change in size and scale to meet new demands
Scalability
The system responsible for translating domain names like example.com into IP addresses
The Domain Name System (DNS)
Write a brief response explaining whether you believe this statement is always true. Explain your reasoning.
The binary pattern 01000001 represents the number 65.
Input
The user clicks a button
A protocol for sending packets that does error checking to ensure all packets are received and properly ordered
Transmission Control Protocol (TCP)
A protocol for sending packets quickly with minimal error-checking and no resending of dropped packets
User Datagram Protocol (UDP)
The inputs and outputs that allow a user to interact with a piece of software. User interfaces can include variety of forms such as buttons, menus, images, text, and graphics
User interface
Redundancy in networks belongs to single point of failure to ensure better network stability and uptime in the face of events that would usually take the network offline.
What are the benefits of building redundancy into a network? What are the potential issues with building redundancy?
Other fractional values from the decimal number system (ex: 0.39)
What can binary NOT precisely represent?
Some fractional amounts from the decimal number system
What can binary precisely represent?
A sequential program starts from beginning to end and an event driven program is something that waits for something else to occur.
What is the difference between a sequential program and an event-driven program?
The data is transformed to usually make it smaller. It can always be re-constructed back to the original.
What is the most important quality of lossless compression?
The score is: 4
What will the value of score be at the end of the program? Note: <- is used to represent a left facing arrow var score score <- 3 score <- score + 1 score <- "The score is: " + score
The music and text categories would be used best in the lossless compressions because their quality can be reversed and the data reduction is lower. The image and video categories would be used best in lossy compressions because although it reduces the quality, most times the human eye cannot recognize the change.
You've been given a new cell phone with a 2 gigabyte data plan. You plan to use your phone for text messages, images, video, and music. Which of these categories are best compressed using lossless compression? Which of these categories are best compressed using lossy compression? Why?