Computer Science Ultimate Study Guide
decryption
A process that reverses encryption, taking a secret message and reproducing the original plain text.
Jesse purchases a new smartphone and is immediately able to use it to send a photo over the Internet to a friend who lives in a different country. Which of the following is NOT necessary to make this possible?
A single direct connection is established between any two devices connected to the Internet
Which of the following is true of intellectual property?
Creative Commons enables content creators to freely distribute their otherwise copyrighted work.
Your computer uses 4 bits to represent decimal numbers (0, 1, 2, 3 and so on) in binary. What is the SMALLEST number for which an overflow error occur?
16
Convert the decimal (base-10) number 20 to binary (base-2).
10100
Which of the following binary (base-2) numbers is LARGEST?
11000000
A sequential algorithm is broken into three stages Sequential Algorithm Time · Download stage: 1 minute · Sorting stage: 6 minutes · Upload stage: 1 minute A parallel version of the algorithm completes the sorting stage in parallel leading to a new set of times Parallel Algorithm Time · Download stage: 1 minute · Sorting stage: 2 minutes · Upload stage: 1 minute What is the speedup of the parallel solution?
2
How many total numbers can be represented with an 8-bit binary (base-2) system?
256
A computer is performing a binary search on the sorted list of 7 numbers below. What is the maximum number of iterations needed to find the item? [1, 5, 20, 50, 51, 80, 99]
3
Convert the binary (base-2) number 1001 to decimal (base-10).
9
Which of the following best describes how computing devices represent information?
A computer represents data as bits which is either a 0 or a 1
encryption
A process of encoding messages to keep them secret, so only "authorized" parties can read it.
Which of the following situations is most likely to cause issues arising from the digital divide?
A state makes voter registration forms available only by visiting a government website
phishing
A technique that attempts to trick a user into providing personal information. That personal information can then be used to access sensitive online resources, such as bank accounts and emails.
rogue access point
A wireless access point that give unauthorized access to secure networks.
Arman takes a picture with his smartphone which he subsequently posts online. Beatrice finds the picture online and posts a copy of it on her website with an attached Creative Commons license. Which of the following best describes who owns the photo?
Arman owns the photo because he was the original creator and did not license the work.
This is NOT how computers represent complex information
Abstraction helps represent complex information by surfacing complexity that might otherwise be hidden
Which of the following best describes the existence of undecidable problems?
An undecidable problem is a problem for which no algorithm can be constructed that always produces a correct output
Which of the following is NOT a reason to include comments in programs
Comments help the computer decide whether certain components of a program are important.
A researcher is interested in learning more about the different kinds of plants growing in different areas of the state she lives in. The researcher creates an app that allows residents of the town to photograph plants in their area using a smartphone and record date, time, and location of the photograph. Afterwards the researcher will analyze the data to try to determine where different kinds of plants grow in the state. Which of the following does this situation best demonstrate?
Citizen Science
A restaurant is interested in learning about the food preferences of people living nearby to the restaurant and intends to use survey data to help decide which new items to add to the menu. Which of the following is LEAST likely to be part of the process used to analyze the data?
Cleaning a data visualization to remove unwanted patterns
In which of the following situations would parallel systems MOST likely be used to help analyze data?
Data analysis involving large datasets
Which of the following best describes the purpose of a design specification?
Describing the requirements for how a program will work or users will interact with it
Which of the following is true of algorithms?
Every algorithm can be constructed using combinations of sequencing, selection, and iteration
Which of the following algorithmic efficiencies would be considered LEAST efficient?
Exponential
A photographer stores digital photographs on her computer. In this case the photographs are considered the data. Each photograph also includes multiple pieces of metadata including: · Date: The date the photograph was taken · Time: The time the photograph was taken · Location: The location where the photograph was taken · Device: Which camera the photo was taken with Which of the following could the photographer NOT do based on this metadata?
Filter photos to those taken of buildings
Which of the following is true of functions?
Functions can help remove repeated code from a program
A school is creating class schedules for its students. The students submit their requested courses and then a program will be designed to find the optimal schedule for all students. The school has determined that finding the absolute best schedule cannot be solved in a reasonable time. Instead they have decided to use a simpler algorithm that produces a good but non-optimal schedule in a more reasonable amount of time. Which principle does this decision best demonstrate?
Heuristics can be used to solve some problems for which no reasonable algorithm exists
Which of the following Internet protocols is used to request and send pages and files on the World Wide Web?
HyperText Transfer Protocol (HTTP)
Which of the following best describes the purpose of an IP address?
IP addresses provide a unique number for identifying devices that send and receive information on the Internet
Which of the following BEST describes the differences between sequential and event-driven programming?
In sequential programming commands run in the order they are written. In event-driven programming some commands run in response to user interactions or other events.
Computing Innovation
Includes a program as an integral part of its function. 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).
Personally identifiable information
Information about an individual that identifies, links, relates, or describes them.
symmetric key encryption
Involves one key for both encryption and decryption.
Which of the following is true of lossy and lossless compression algorithms?
Lossy compression algorithms are typically better than lossless compression algorithms at reducing the number of bits needed to represent a piece of data.
Ryan is designing an app that needs to quickly send low quality photos between users. Most smartphones take much higher quality photos than Ryan needs for his app. Which answer best describes the type of compression Ryan should choose and why?
Lossy compression since it typically results in smaller data sizes.
A group of students writes their names and unique student ID numbers on sheets of paper. The sheets are then randomly placed in a stack. Their teacher is looking to see if a specific ID number is included in the stack. Which of the following best describes whether their teacher should use a linear or a binary search?
Only the linear search will work since the data has not been sorted
A town decides to publicize data it has collected about electricity usage around the city. The data is freely available for all to use and analyze in the hopes that it is possible to identify more efficient energy usage strategies. Which of the following does this situation best demonstrate?
Open Data
Which of the following is true of how packets are sent through the Internet?
Packet metadata is used to route and reassemble information travelling through the Internet
public key 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.
Which of the following is a benefit of parallel and distributed computing?
Parallel computing scales more effectively than sequential computing
Which of the following is MOST likely to be an outcome of the digital divide
People from some racial or ethnic groups have unequal access to computing technology.
An Internet Service Provider (ISP) is a company that builds the routers and wired connections that allow individuals to access the Internet. An ISP is considering adding additional redundant connections to its network. Which of the following best describes why the company would choose to do so?
Redundant networks are more reliable
The following algorithm is followed by a person every morning when they get up from bed to go to school 1. Wake up 2. Brush teeth 3. Put on shirt 4. Put on pants 5. Put on socks 6. Put on shoes 7. Tie shoes Which concept does this algorithm BEST demonstrate?
Sequencing
malware
Software intended to damage a computing system or to take partial control over its operation.
This quizlet just includes the terms and questions that could fit on it. There are questions over codes and graphs on the study guide that couldn't go on here, and they are going to be on the test as well. You might want to study those as well. Good luck!
Study Hard, Gamers
A bank is developing an algorithm that will help them decide who to make loans to. As input the algorithm will consider information about the person applying for the loan and the amount of money requested, and as output the algorithm will decide whether the bank should give that loan. The bank intends to develop the algorithm using machine learning techniques. The algorithm will be trained using data from past loan decisions made by human bankers. Which of the following best describes whether this algorithm will include bias?
The algorithm will likely reflect the human biases in the data used to train it
A software company used to run an algorithm sequentially on one server. As more users start using their app, the company decided to rewrite the program to be parallel. It is now run on four separate servers instead of one Thanks to the use of a parallel algorithm, the same process that used to take 40 minutes to run now only requires 20 minutes. The company is considering purchasing additional computers to decrease the time the program runs even further. Which of the following best describes the impacts of running the parallel algorithm on an even larger number of computers
The algorithm will likely require less time to run though the improvements in efficiency will not be as significant as before.
A job placement agency helps match job seekers with potential employers. The agency would like to design a simulation in order to help predict the likely job placement outcomes for job seekers based on historical trends and patterns. Which of the following is most likely to be a benefit of the simulation?
The computer simulation could be used to test hypotheses about patterns in the job placement process that are costly or time consuming to observe in reality.
Jorge is sending a large image file to a friend as part of a shared classroom project. Which of the following is most likely true if Jorge opts to compress the image before sending it?
The image will require fewer bits in order to be represented.
Emilee is watching an online video. The video is being sent to her laptop by a server over the Internet which splits the video into packets and sends them in the order they appear in the video. Which of the following is true about how the packets will arrive at her computer?
The packets may arrive out of order
When visiting a museum Lian takes a photo of a painting with a smartphone which stores the photo as an image file. Which of the following best describes the differences between the painting itself and the photo of the painting stored on the smartphone?
The photo is a digital representation of the analog painting
This question refers to the same collection of photos and their metadata described in the previous question. Due to a computer error, the Time metadata for all of the photographs is accidentally set to the same time of day. The other pieces of metadata and the data itself are not affected by the error. Which of the following is MOST likely to be the result of this problem?
The photographer will not be able to filter to photographs taken in the morning
A school is developing a program to keep track of information about students and their class schedules. In which of the following instances would a data abstraction be most helpful?
The program includes individual variables to store the names of each student rather than a single list of students.
Which of the following best describes the protocols used on the Internet?
The protocols of the Internet are open and used by all devices connected to the network
Which of the following is true of how the Internet has responded to the increasing number of devices now using the network?
The protocols of the Internet were designed to scale as new devices are added
keylogging
The use of a program to record every keystroke made by a computer user in order to gain fraudulent access to passwords and other confidential information.
Which of the following Internet protocols is MOST important in reassembling packets and requesting missing packets to form complete messages?
Transmission Control Protocol (TCP)
Lucy is completing a project as part of a science class using materials she found online. Which of the following is MOST LIKELY to lead to legal consequences?
Using images posted online by another student without permission or citation.
The mayor of a city is interested in learning what goals are most important for residents of the city. Members of her staff visit one of the many neighborhoods in the city and ask 20 residents to fill out a survey. The mayor is concerned that the survey may be biased and not accurately reflect the overall interests in her town. Which of the following strategies is MOST likely to address concerns about the data being biased or inaccurate
Visiting multiple new neighborhoods to collect more survey responses
Which of the following is true of how computers represent numbers?
With a fixed number of bits some numbers are too large to represent in a computer which will lead to overflow errors.
Choose the correct definition for Conditional Statement
affects the sequential flow of control by executing different statements based on the value of a Boolean expression
Two devices are connected to the Internet and communicating with one another. A squirrel chews through one of the wires in the network that is currently being used by the devices to communicate. The network immediately begins using a different path through the network and communication continues as normal. This situation best exemplifies which principle?
fault-tolerance
In which of the following stages of the development process is a team MOST likely to interview a potential user of an app?
investigating and reflecting
wordList is a list of words that currently contains the values ["tree", "rock", "air"] Which of the following lines will result in the list containing the values ["air", "rock", "air"]
wordList[0] = wordList[2]
