CSP BIG IDEA 2 Digital Information

When is it most beneficial to use a heuristic?

When the problem cannot be solved in a reasonable time and an approximate solution is acceptable

A photographer manipulates an image by lightening each RGB value by adding 20. What type of transformation is the photographer using?

Lossless transformation

What is true about data compression?

There are trade-offs involved in choosing a compression technique for storing and transmitting data.

What best describes the result of using 64-bit integers instead of 32-bit integers in a website (that counts how many times a video is played)?

2^32 times as many values can be represented

What are units of bytes in ascending order?

KB, GB, TB

An artist makes an RGB image with each pixel color encoded with 12-bits --- 4 bits each for red, green and blue. What is the hexadecimal value for Red as a 12-bit representation?

F00

A compression scheme may use long strings of bits (called run-length) which can be uncompressed back into its original binary state. What type of compression is this?

Lossless compression

A MP3 audio compression may identify and remove frequencies that cannot be heard by humans while keeping the file sounding the same as the original. What type of compression is this?

Lossy compression

How many times bigger (in bytes) is a MB than a KB?

1000 times bigger

What is data about data?

metadata

What data can be provided to a company's employees without endangering the anonymity of a customer?

B (Last item purchased, Product category preference, average purchase amount ($))

What is an advantage of sharing a file physically as a hard copy instead of sharing it digitally?

C (Easier for common users to annotate and take notes on)

What is the most helpful for a student to look at to estimate the likelihood of getting into a certain college?

C (GPA and SAT scores vs. Accepted scores)

What is the best reason for a computer scientist to work with someone outside their field?

D (Help draft goal of what to look for)

A graph summarizes per capita meat consumption in the US. What can be concluded?

C (The ratio of chicken to beef consumption is increasing)

What is not a scenario in which you would need a computer program that analyzes and searches for patterns in data?

B (A video hosting site to analyze the views for all videos and create a list of the top ten most viewed videos.)

What can weather websites do?

C (Transform the data into whichever one the user has indicated they prefer, as this makes it easier for the user to gain insight and knowledge from the data.)

What is not a reason to represent a large data set in a visualization?

B (A visualization will always represent all of the data without obscuring the meaning of the data set)

What is a computer not able to collect information on for a website that shows ranks of given baby names?

D (Determining the reason a name gained popularity)

Which statements are true when dealing with huge quantities of information?

i. Storing large quantities of data over the internet poses a data access challenge.
ii. Analyzing large quantities of data requires significant computational power.
iii. Algorithms used to process large quantities of data tend to be very sophisticated.

D (I, II, & III)

Why would an engineer design stereos and mixing boards showing where sound levels are when music is being played?

A (Visuals can communicate information about data)

What is not an example of metadata?

D (Wikipedia main page)

What is true about encrypted and compressed large files?

B (You need to send the compressed text and the key)

What can be used to communicate knowledge gained from data through graphs, tables, or diagrams?

C (A colorful infographic of the data)

Why may positive support that is left in accounts that are made to gather concerns be a problem?

B (Harder to find the actionable complaints)

What is the least threatening to the security of corporate data?

D (Computer network disruptions)

What best characterizes the ability of modern computers to process quantitative and qualitative data?

A (Computers, when programmed using appropriate algorithms, can effectively process both quantitative and qualitative data)

What are examples of security measures used to before information is transmitted?

i. Two-factor authorization
ii. Test image
iii. Facial Recognition

D (I, II, and III)

How can you analyze your own data to offer chances to highlight characteristics found important or news worthy?

i. Adjusting the scale of the y-axis to emphasize difference
ii. Using different statistical methods to find the average
iii. Reporting statistics on a given category instead of the entire population

D (I, II, and III)

What is not an example of collaboration?

A (Seth and Alex)

How may attributes of a photo be used by courts and police to settle disputes?

B (The owner to confirm location and potentially use phone GPS to support location)

What is the best advantage of collaborating with a family member to research a family line instead of looking alone?

B (Allows you to cross reference stories for accuracy or trends)

What is best supported by data in a spreadsheet showing the size of the US economy?

C (The GDP is trending upwards)

Why may a website restrict the size of files shared by high schools below a certain size?

B (To minimize storage on their webserver)

What is an example of metadata in a letter?

C (The envelope, containing addresses, a stamp, and a postmark)

What is a false statement about a submarine cable table and map?

A (The map communicates information about the submarine data much better than the table)

What can not be answered by using only the information in the table and map?

C (Which country uses the most data?)

What is metadata?

Data about (other) data.

What correlations could be drawn from two visualizations shown of Republican vs Democratic votes and the state universities in Florida?

C (Most of the counties that contain a state university voted for a Democratic candidate)

What is the biggest concern in following press reports concerns following AP Computer Science Principles standard?

B (Maintaining privacy of large data sets containing personal information can be challenging)

What is not a trade-off that needs to be considered in the AWS platform, which makes it easier for other companies to establish a web presence?

D (Location of where data is held)

The following information is summarized and stored in a publicly available movie purchase database.

i. The day and date each movie was purchased
ii. The title of each movie purchased
iii. The cities where subscribers purchased each movie
iv. The number of times each movie was purchased by subscribers in a given city

What CANNOT be determined using only the information in the database?

The number of movies purchased by an individual subscriber for a particular month

A social media site contains the following metadata:

i. The time the message was posted
ii. The name of the user who posted the message
iii. The names of any users who comment on the message and the times the comments were made

What goal would be more useful to analyze the data instead of the metadata?

To determine the topics that many users are posting about

A computer program uses 3 bits to represent integers. When the program adds the decimal (base 10) numbers 5 and 3, the result is 0. What happened?

An overflow error occurred.

A set of info about students major in CS in colleges contains the info:

i. The student's gender
ii. The state in which the student attends ollege
iii. The student's grade point average on a 4.0 scale

What question could be answered by analyzing only information in the data set?

How many states have a higher percentage of female computer science majors than male computer science majors attending college in that state?

i. Item identification number
ii. Footwear type (sneakers, boots, sandals, etc.)
iii. Selling price (in dollars)
iv. Size
v. Color
vi. Quantity available

Using only this database in a footwear store, what can be determined?

Which items listed in the database are not currently in the store

For each wild animal wearing tracking collars, the following geolocation data is collected at frequent intervals:

i. The time
ii. The date
iii. The location of the animal

What question about a particular animal can not be answered with the data?

Do the movement patterns of the animal vary according to the weather?

A photographer is manipulating a digital image and overwriting the original image. Which of the following describes a lossless transformation of the digital image?

Creating the negative of an image by creating a new RGB triplet for each pixel in which each value is calculated by subtracting the original value from 255.

The negative of an image is reversed from the original;light areas appear dark, and colors are reversed.

What statement about browsing sessions in an anonymous window is true?

Items placed in a Web store's shopping cart for future purchase during the anonymous browsing session will not be saved on the user's computer

What statement describes a limitation of using a computer simulation to model a real-world object or system?

Computer simulations usually make some simplifying assumptions about the real-world object or system being modeled.

Which of the following is considered an unethical use of computer resources?

Purchasing a single-user copy of photo editing software and installing it on all computers in a computer lab

How do computing devices represent information?

Computers use binary to represent information with individual bits using ones 1s and 0s on and off.

How does an overflow error occur?

When you try to represent a larger number that you don't have enough bits to represent because it's too large.

If a computer uses 6 bits to represent decimal numbers in binary, what is the smallest number for which an overflow error occurs?

64

How many numbers can be represented with a 6-bit binary number?

64

What is the largest number you can represent with a 6-bit binary number?

63

What is an advantage of using a larger base number system versus a smaller base number system? Examples: hexadecimal (base-16) versus decimal (base-10) OR decimal (base-10) versus binary (base-2)?

When using a larger base number system gives you more variety in colors, numbers, symbols with less digits.

Which of the following can be represented by a single binary digit? Select TWO.
A)The position of the hour hand of a clock
B)The value of a Boolean variable*
C)The remainder when dividing an integer by 2
D)The volume of a radio speaker

B C

A computer program uses 4 bits to represent integers. When the program adds the decimal numbers 5 and 11, the result is 0

A round-off error occurred

A bakery collects data on sales. Each sales record includes the date of the sale and some metadata about the items that were part of the sale. The data includes: the names of the items sold, the types of items sold, the number of each item sold, and the price of each item sold. Which of the following CANNOT be determined from the bakery's data set?

A. The total income from sales the bakery received in the past month.

B. Which customer most frequently purchases bread.

C. The item bought in the highest quantity in the past week.

D. Days when certain items sell the most.

B. Which customer most frequently purchases bread

Consider the following numbers given in Binary (BIN), Decimal (DEC), and Hexadecimal (HEX) representations:

BIN: 1110

DEC: 13

HEX: F

Which of the following lists the numbers in order from least to greatest?

A. BIN: 1110, DEC: 13, HEX: F

B. DEC: 13, BIN: 1110, HEX: F

C. DEC: 13, HEX: F, BIN: 1110

D. HEX: F DEC: 13, BIN: 1110

B. DEC: 13, BIN: 1110, HEX: F

A programmer is writing a system that is intended to be able to store large amounts of personal data. As the programmer develops the data system, which of the following is LEAST likely to impact the programmer's choices in designing the structure of the system?

A. Maintaining privacy of the information stored in the data set.

B. Scalability of the system.

C. Structuring the metadata of the information for analysis.

D. The frequency of a particular item occurring in a data set.

D. The frequency of a particular item occurring in a data set.

A certain social media Web site allows users to post messages and to comment on other messages that have been posted. When a user posts a message, the message itself is considered data. In addition to the data, the site stores the following meta data.

The time the message was posted
The name of the user who posted the message
The names of any users who comment on the message and the times the comments were made

For which of the following goals would it be more useful to analyze the data instead of the metadata?

A. To determine the users who post messages most frequently

B. To determine the time of day that the site is most active

C. To determine the topics that many users are posting about

D. To determine which posts from a particular user have received the greatest number of comments

C. To determine the topics that many users are posting about

The Chart below from Google Trends shows the prevelance of some search terms in the United States between 2004 and the present. Which of the following is the most accurate statement of what this chart is showing.


A. Since sometime around 2009, red has become the favorite color of more people

B. Generally speaking, since 2009 more people use "red" in their search terms more than they use "blue", "yellow", "green", or "purple"

C. The general decline in the search term "yellow" might be due to the decline of searches for yellow taxis, as car sharing services have become more popular

D. Generally speaking, the volume of internet searches is increasing over time because the number of people using the internet is also increasing.

B. Generally speaking, since 2009 more people use "red" in their search terms more than they use "blue", "yellow", "green", or "purple"

The AP CS Principles framework contains the following statement:

7.1.1G Search trends are predictors.

Which of the following is the most accurate statement about using search trends as predictors of future events?

A. Search trends are imperfect predictors of future events that fully represent society at large.

B. Search trends are accurate and reliable predictors of future events that fully represent society at large.

C. Search trends are imperfect predictors of future events that may not fully represent society at large.

D. Search trends are accurate and reliable predictors of future events that may not fully represent society at large.

C. Search trends are imperfect predictors of future events that may not fully represent society at large.

Amara is tasked with cleaning the data to prepare it for further analysis. Which of the following would be the least appropriate modifications to make to the data to prepare it for further analysis?

A. Translate all states into their two-letter state code

B. Group similar areas of study into a single area of study. For example: grouping Applied Mathematics and Mathematics together into "Mathematics"

C. Round up all non-integer values for "Likelihood of staying in state"

D. Removing the entire row with home state "adsfas" and recomputing

C. Round up all non-integer values for "Likelihood of staying in state"

Amara plans to use the survey data to create a visualization and short write up about students' plans for college, but first she wants to learn more about how the survey was conducted. Of the following things she might learn about the survey, which are the most likely sources of bias in the results based how it was collected?

Choose two answers.

A. She learns that the survey administrators only asked a representative sample of students, rather than every student in each state.

B. She learns that responses were collected only by mobile app.

C. She learns that the survey was only available to students who scored at the top 10% on the PSAT.

D. She learns the survey was available to complete in both digital and paper form.

B. She learns that responses were collected only by mobile app.
C. She learns that the survey was only available to students who scored at the top 10% on the PSAT.

Mary, a high school administrator, is analyzing a large amount of data about the students at her school to determine the most efficient bus routes.
The data includes information about each household: the names of students in the household, the address, which schools the students attend, and whether or not
they take the bus. Before Mary analyzes her data, she uses a computer program to clean it.
What are the benefits of cleaning the data before she analyzes it?

This eliminates incorrect or irrelevant data that might skew her analysis.

Mary has cleaned her data and is ready to determine the most efficient bus route. She starts by splitting the city into four regions on a map, then she uses a computer
program to sort her data into four different groups according to the regions. This way she can examine how many students use the bus in each region of the city.
Mary starts prioritizing bus routes based on regions, but one of her fellow administrators suggests that she use her computer program to sort her data a different way first. Why might this be useful?

Transforming the data might help Mary notice a different pattern that makes a bigger impact on bus routes than regions of the city.

Most stereos and mixing boards provide a graph that shows where the sound levels are for a piece of music being played. ADJ can look at this read out in real time
through their equipment. This histogram of various noise levels allows them to adjust settings to get the sound they are looking for at an event.
Which of the following is the BEST reason the engineer would have designed the set up in this way?

Visuals can communicate information about data.

Webpages store metadata that helps search engines locate them. Which of the following is NOT an example of meta data stored within the site?

Contact information

Wireless companies collect metadata for each phone call made on their network, including the number of the caller, the number called, the location of the cell tower
used for your call, and the duration of each call.
Which of the following can NOT be discovered from the metadata collected by cell phone companies?

A. What was said in your phone conversation.

Companies spend a lot of time and effort collecting information into large data sets which they interrogate to search for patterns in the data.
Which of the following are examples where searching for patterns in the data could help answer a question or verify a hypothesis?
Select TWO answers.

A high school principal analyzes the current grades across subjects of all junior students to try to determine which students will likely enroll at the local college.

An online search engine analyzes the buying habits of its users to determine what types of products the user may be interested in purchasing in the
future.

Occasionally a teacher is faced with a situation where a student is handing in an assignment that is suspected of not being genuine. If a teacher suspects that a
student has submitted an assignment that they did not generate, they have the option of using metadata to verify the origin of the file.
Which of the following could be used as metadata to determine the origin of a file?
I. Author of the file
II. IP address where file was made
III. Date created

I and III only

Which of the following questions could NOT be answered by analyzing only the information above?

Do students who go to a high school in Georgia have higher grade point averages than those who go to a high school in Florida?

There is growing preference in today's age for streaming music over purchasing music. For what reasons might people prefer streaming over purchasing music?

Purchasing and downloading music takes up storage space on the device.

Which of the following is NOT an example of security and privacy concerns that arise from storing data digitally?

A manager looks up an employee's birthday in the online company directory in order to plan a surprise birthday party for them at the office.

Data compression is the process of transforming a file so that it uses less bits than the original file, thereby reducing its file size.
Which of the following is NOT true concerning data compression?

A compressed file cannot be restored to its original format unless the person trying to restore the file has decryption rights.

A freshman in a college statistics class created and conducted a survey asking other students about their personal hygiene routines. She created am online form that recorded answers in a spreadsheet and decided to send the form to every student at the university so that they could enter their answers to the survey questions themselves. After the survey was over, she published the results by changing the spreadsheet's access to "view only" and making it public.
The following survey questions were asked and this information was entered by the individual students into the shared spreadsheet:
Of the following, which is the LEAST likely to be an issue with this approach?

A participant changes his/her published hygiene information to match the hygiene habits of other students.

Tyrese is editing and applying a filter to his picture so that he can upload it to his social media page. Filters work by manipulating the RGB colors of the image and replacing the original image with the new image.
Which of the following is considered lossless?

1) Increasing the scale of all blue pixels by 50 to make the sky look richer.
2) Turning down the brightness of the image by decreasing all three colors by 75